U.S. patent number 10,117,932 [Application Number 13/708,014] was granted by the patent office on 2018-11-06 for uses of immunoconjugates targeting cd138.
This patent grant is currently assigned to BIOTEST AG, IMMUNOGEN INC.. The grantee listed for this patent is Biotest AG, ImmunoGen, Inc.. Invention is credited to Katrin Bernoester, Christoph Bruecher, Benjamin Daelken, Andre Engling, Marcus Gutscher, Thomas Haeder, Martin Koenig, Gabriele Niemann, Frank Osterroth, Gregor Schulz, Christoph Uherek, Andrea Wartenberg-Demand, Chantal Zuber.
United States Patent |
10,117,932 |
Schulz , et al. |
November 6, 2018 |
Uses of immunoconjugates targeting CD138
Abstract
Disclosed is a method and composition for treating a disease
associated with target cells expressing CD138 in a multiple dose
regimen. An immunoconjugate comprising an engineered targeting
antibody targeting CD138 expressing cells and an effector molecule
is administered in a multiple dose regimen. The multiple dose
regimen comprises at least two doses and the aggregate dose
administered within an active treatment cycle is an aggregate
maximum tolerable dose (AMTD) or a fraction of the AMTD. The AMTD
and/or said fraction exceeds the dose resulting in dose limiting
toxicity (DLT) and/or exceeds the maximum tolerable dose (MTD) when
the immunoconjugate is administered as a single dose, including as
part of a multiple single dose regimen within said active treatment
cycle.
Inventors: |
Schulz; Gregor (Umkirch,
DE), Osterroth; Frank (Dietzenbach, DE),
Haeder; Thomas (Dreieich, DE), Bruecher;
Christoph (Eschborn, DE), Niemann; Gabriele
(Walzbachtal, DE), Engling; Andre (Bad Homburg,
DE), Uherek; Christoph (Seligenstadt, DE),
Daelken; Benjamin (Frankfurt am Main, DE),
Wartenberg-Demand; Andrea (Schrecksbach, DE), Zuber;
Chantal (Ulm, DE), Gutscher; Marcus (Langen,
DE), Bernoester; Katrin (Wiesbaden, DE),
Koenig; Martin (Wiesbaden, DE) |
Applicant: |
Name |
City |
State |
Country |
Type |
Biotest AG
ImmunoGen, Inc. |
Dreieich
Waltham |
N/A
MA |
DE
US |
|
|
Assignee: |
BIOTEST AG (DE)
IMMUNOGEN INC. (Waltham, MA)
|
Family
ID: |
47326154 |
Appl.
No.: |
13/708,014 |
Filed: |
December 7, 2012 |
Prior Publication Data
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|
|
Document
Identifier |
Publication Date |
|
US 20140010828 A1 |
Jan 9, 2014 |
|
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
|
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61722367 |
Nov 5, 2012 |
|
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61568640 |
Dec 8, 2011 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
A61K
47/6809 (20170801); A61K 39/39558 (20130101); A61K
47/6851 (20170801); A61P 35/00 (20180101) |
Current International
Class: |
A61K
49/00 (20060101); A61K 47/68 (20170101); A61K
39/00 (20060101); A61K 39/395 (20060101) |
Field of
Search: |
;424/9.1,9.2,130.1,134.1,138.1,141.1,152.1 |
References Cited
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|
Primary Examiner: Swartz; Rodney P
Attorney, Agent or Firm: Agris & von Natzmer LLP von
Natzmer; Joyce
Claims
What is claimed is:
1. A method for treating a disease associated with target cells
expressing CD138 comprising: administering to a subject in need
thereof an immunoconjugate comprising at least one engineered
targeting antibody targeting CD138 expressing cells, and at least
one maytansinoid, wherein said engineered targeting antibody is
functionally attached to said maytansinoid to form said
immunoconjugate, wherein at least a part of the engineered
targeting antibody confers IgG4isotype properties, wherein the
immunoconjugate is administered in intervals of less than 11.1 days
within a period of 21 days constituting a multiple dose regimen,
wherein the aggregate dose administered within an active treatment
cycle is an aggregate maximum tolerable dose (AMTD) or a fraction
of the AMTD and wherein said AMTD and/or said fraction exceeds the
dose resulting in dose limiting toxicity (DLT) when the
immunoconjugate is administered as a single dose, including as part
of a multiple single dose regimen and/or exceeds the maximum
tolerable dose (MTD) when the immunoconjugate is administered as a
single dose, including as part of a multiple single dose regimen
within said active treatment cycle, wherein the active treatment
cycle includes the administering being performed at least once a
week for at least three weeks and the active treatment cycle is
followed by a resting period of at least one week, which together
define a treatment cycle of at least 28 days, and wherein, after
one, two or more treatment cycles, at least stable disease is
achieved.
2. The method of claim 1, wherein the immunoconjugate is
administered at least three times within said 21 days.
3. The method of claim 1, wherein the immunoconjugate is
administered in equal doses.
4. The method of claim 1, wherein said multiple dose regimen lasts
at least 3 weeks and is followed by a resting period.
5. The method of claim 4, wherein progression free survival or
stable disease is maintained during the resting period.
6. The method of claim 5, wherein a level of said immunoconjugate
in a body fluid of said subject, during said resting period is at
least 0.5 .mu.g/ml, at least 1 .mu.g/ml, at least 2 .mu.g/ml, at
least 3 .mu.g/ml, 4 .mu.g/ml, 5 .mu.g/ ml or 6 .mu.g/ml and/or
wherein more than 80%, more than 90%, more than 95% of the CD138 of
isolated target cells are occupied by said immunoconjugate within
four to twenty four hours after completion of administration of the
immunoconjugate.
7. The method of claim 1 wherein the AMTD exceeds the dose of said
DLT by at least 20%, at least 30%, at least 40%, at least 50%, at
least 60%, at least 80%, at least 90%, at least 100% or at least
120% and said MTD by at least 30%, at least 40at least 50%, at
least 60%, at least 80%, at least 90at least 100%, at least 120% or
at least 140%.
8. The method of claim 1, wherein the AMTD is at least 240
mg/m.sup.2, 300 mg/m.sup.2, 360 mg/m.sup.2, or 420 mg/m.sup.2 and
the dose resulting in said DLT is 200 mg/m.sup.2 or the AMTD is at
least 240 mg/m.sup.2, 300 mg/m.sup.2, 360 mg/m.sup.2, or 420
mg/m.sup.2 and said MTD is at least 160 mg/m.sup.2 or at least 180
mg/m.sup.2.
9. The method of claim 1, wherein at least stable disease is
maintained during three, four, five, six, seven treatment
cycles.
10. The method of claim 9, wherein after reaching at least stable
disease, the immunoconjugate is administered as a maintenance
therapy less than twice within said active treatment cycle as a
repeated single dose of between 60 mg/m.sup.2 and 280 mg/m.sup.2,
including about 70 mg/m.sup.2, about 80 mg/m.sup.2, about 90
mg/m.sup.2, about 100 mg/m.sup.2 , about 110 mg/m.sup.2, about 120
mg/m.sup.2, about 130 mg/m.sup.2, about 140 mg/m.sup.2, 150
mg/m.sup.2, about 160 mg/m.sup.2, about 170 mg/m.sup.2, about 180
mg/m.sup.2, about 190 mg/m.sup.2, about 200 mg/m.sup.2, about 210
mg/m.sup.2, about 220 mg/m.sup.2, about 230 mg/m.sup.2, about 240
mg/m.sup.2, about 250 mg/m.sup.2, about 260 mg/m.sup.2 and about
270 mg/m.sup.2.
11. The method of claim 10, wherein the disease associated with
target cells expressing CD138 is relapsed/refractory myeloma and
wherein at least progression free survival, stable disease and or a
minor response is obtained for more than 3 months during said
maintenance therapy.
12. A method of claim 1, wherein administration of said
immunoconjugate as a repeated multiple dose in said active
treatment cycle, results in an aggregate effective amount and a
first level of the immunoconjugate in a body fluid of the subject
and wherein, an amount equivalent to said aggregate effective
amount is administered as a single dose or repeated single dose in
said active treatment cycle, results in a second level of the
immunoconjugate in a body fluid of said subject, wherein the first
level is equal or below the second level.
13. The method of claim 12, wherein the active treatment cycle
lasts 21 days and/or the repeated multiple dose consists of 3
administrations of equal doses.
14. The method of claim 12, wherein said aggregate effective amount
is more than 200 mg/m.sup.2, about 220 mg/m.sup.2, about 240
mg/m.sup.2, about 260 mg/m.sup.2, or about 280 mg/m.sup.2.
15. The method of claim 1, wherein administration of said
immunoconjugate as a multiple dose regime results, 0-2 hours after
completion of administration in a mean plasma level of at least 7
.mu.g/ml, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22,
23, 24, 25, 26, 27, 28, 29, 30, 40, 50, 60 or 70 .mu.g/ml.
16. The method of claim 1, further comprising determining 0-2 hours
following a completion of administering an individual dose of said
immunoconjugate or a pharmaceutical composition comprising the
same, a level of said immunoconjugate in a body fluid, determining
whether the level of the immunoconjugate is below or above 7
.mu.g/m.sup.2, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20
.mu.g/m.sup.2, increasing the individual dose in the next treatment
cycle by at least 10 mg/m.sup.2, 20 mg/m.sup.2, about 30
mg/m.sup.2, about 40 mg/m.sup.2, about 50 mg/m.sup.2, about 60
mg/m.sup.2, 70 mg/m.sup.2, about 80 mg/m.sup.2, about 90 mg/m.sup.2
or about 100 mg/m.sup.2 if the level is below 7 .mu.g/m.sup.2, 8,
9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 .mu.g/m.sup.2, or
maintaining or decreasing by at least 10 mg/m.sup.2, 20 mg/m.sup.2,
about 30 mg/m.sup.2, about 40 mg/m.sup.2, about 50 mg/m.sup.2,
about 60 mg/m.sup.2, about 70 mg/m.sup.2, about 80 mg/m.sup.2,
about 90 mg/m.sup.2 or about 100 mg/m.sup.2, the individual dose in
the next treatment cycle if the level is above 7 .mu.g/m.sup.2, 8,
9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20 .mu.g/m.sup.2.
17. The method of claim 1, wherein the at least one maytansinoid is
N.sup.2'-(4-methyl-4-mercapto-1-oxopentyl)-maytansine (DM4) or
N.sup.2-deacetyl-N.sup.2-(3-mercapto-1-oxopropyl)-maytansine
(DM1).
18. The method of claim 17, wherein the at least one maytansinoid
is DM4.
19. A method for treating a disease associated with target cells
expressing CD138, comprising: administering to a patient in need
thereof a pharmaceutical composition comprising an immunoconjugate
and a pharmaceutically acceptable carrier in an active treatment
cycle which is optionally followed by a resting period, wherein the
immunoconjugate comprises at least one targeting agent targeting
CD138 expressing cells, and at least one maytansinoid, wherein said
targeting agent is functionally attached to said effector molecule
to form said immunoconjugate, and wherein the dose of the
immunoconjugate administered at least once a week is about 20
mg/m.sup.2, about 30 mg/m.sup.2, about 40 mg/m.sup.2, about 50
mg/m.sup.2, about 60 mg/m.sup.2, 70 mg/m.sup.2, about 80
mg/m.sup.2, about 90 mg/m.sup.2, about 100 mg/m.sup.2, about 110
mg/m.sup.2, about 120 mg/m.sup.2, about 130 mg/m.sup.2, about 140
mg/m.sup.2, about 150 mg/m.sup.2 or about 160 mg/m.sup.2, about 170
mg/m.sup.2, about 180 mg/m.sup.2, about 190 mg/m.sup.2, about 200
mg/m.sup.2, about 210 mg/m.sup.2, about 220 mg/m.sup.2, about 230
mg/m.sup.2, about 240 mg/m.sup.2, about 250 mg/m.sup.2, about 260
mg/m.sup.2, about 270 mg/m.sup.2 or about 280 mg/m.sup.2 and the
pharmaceutical composition is administered for at least three weeks
alone or in combination with a cytotoxic agent.
20. The method of claim 19, wherein the active treatment cycle
lasts at least 21 days and the immunoconjugate is administered once
a week at a dose from about 40 mg/m.sup.2 to about 140
mg/m.sup.2.
21. A method for treating a disease associated with target cells
expressing CD138 comprising: administering to a subject in need
thereof an immunoconjugate comprising at least one engineered
targeting antibody targeting CD138 expressing cells, and at least
one maytansinoid, wherein said engineered targeting antibody is
functionally attached to said maytansinoid to form said
immunoconjugate, wherein at least a part of the engineered
targeting antibody confers IgG4 isotype properties, wherein the
immunoconjugate is administered in intervals of less than 11.1 days
within a period of 21 days constituting a multiple dose regimen,
wherein the aggregate dose administered within an active treatment
cycle is an aggregate maximum tolerable dose (AMTD) or a fraction
of the AMTD and wherein said AMTD and/or said fraction exceeds the
dose resulting in dose limiting toxicity (DLT) when the
immunoconjugate is administered as a single dose, including as part
of a multiple single dose regimen and/or exceeds the maximum
tolerable dose (MTD) when the immunoconjugate is administered as a
single dose, including as part of a multiple single dose regimen
within said active treatment cycle, wherein said administration is
followed, after at least two 21 day treatment cycles, each followed
by a resting period, by a further administration of the
immunoconjugate or a pharmaceutical composition comprising the
immunoconjugate.
22. The method of claim 21, wherein the immunoconjugate or a
pharmaceutical composition comprising the same is administered in
said further administration (i) once every three to six weeks or
(ii) at repeated multiple doses, wherein each individual dose of
immunoconjugate is about 10 mg/m.sup.2, about 20 mg/m.sup.2, about
30 mg/m.sup.2, about 40 mg/m.sup.2, about 50 mg/m.sup.2, about 60
mg/m.sup.2, 70 mg/m.sup.2, about 80 mg/m.sup.2, about 90 mg/m.sup.2
or about 100 mg/m.sup.2 lower than the individual dose of a primary
therapy and/or wherein individual doses are administered in
intervals exceeding the interval of the individual doses.
23. The method of claim 21, wherein said effector is a maytansinoid
and wherein a total amount of maytansinoid administered to said
patient within said 21 days is more than 2 mg/m.sup.2, more than 3
mg/m.sup.2, more than 4 mg/m.sup.2, more than 5 mg/m.sup.2, more
than 6 mg/m.sup.2, more than 7 g/m.sup.2, more than 8 mg/m.sup.2,
more than 9 mg/m.sup.2 or more than 10 mg/m.sup.2.
24. The method of claim 21, wherein said immunoconjugate is
administered every 3.sup.rd day, every 4.sup.th day, every 5.sup.th
day or every 6.sup.th day during said three weeks period.
25. A method for treating a disease associated with target cells
expressing CD138 comprising: administering to a subject in need
thereof an immunoconjugate comprising at least one engineered
targeting antibody targeting CD138 expressing cells, and at least
one maytansinoid, wherein said engineered targeting antibody is
functionally attached to said maytansinoid to form said
immunoconjugate, wherein at least a part of the engineered
targeting antibody confers IgG4 isotype properties, wherein the
immunoconjugate is administered in intervals of less than 11.1 days
within a period of 21 days constituting a multiple dose regimen,
wherein the aggregate dose administered within an active treatment
cycle is an aggregate maximum tolerable dose (AMTD) or a fraction
of the AMTD and wherein said AMTD and/or said fraction exceeds the
dose resulting in dose limiting toxicity (DLT) when the
immunoconjugate is administered as a single dose, including as part
of a multiple single dose regimen and/or exceeds the maximum
tolerable dose (MTD) when the immunoconjugate is administered as a
single dose, including as part of a multiple single dose regimen
within said active treatment cycle, further comprising determining
0-4 hours, including at about 1, 2, or 3, following a completion of
administering said immunoconjugate or a pharmaceutical composition
comprising the same, a reference level (RL) of an said
immunoconjugate or of an efficacy blood parameter in a body fluid
of a patient, determining in a subsequent administration of said
immunoconjugate, at 0-4 hours following a completion of said
subsequent administration, a subsequent level (SL) of an said
immunoconjugate or efficacy blood parameter, comparing the RL to
the SL, (i) determining RL>SL, and increasing the aggregate dose
in a treatment cycle following said subsequent administration by
5-100%, including 10-50% or 20-30%, and/or (ii) determining
RL<SL, and decreasing the aggregate dose in a treatment cycle
following said subsequent administration by 5-100%, including
10-50% or 20-30%.
26. A method for treating a disease associated with target cells
expressing CD138 comprising: administering to a subject in need
thereof an immunoconjugate comprising at least one engineered
targeting antibody targeting CD138 expressing cells, and at least
one maytansinoid, wherein said engineered targeting antibody is
functionally attached to said maytansinoid to form said
immunoconjugate, wherein at least a part of the engineered
targeting antibody confers IgG4 isotype properties, wherein the
immunoconjugate is administered in intervals of less than 11.1 days
within a period of 21 days constituting a multiple dose regimen,
wherein the aggregate dose administered within an active treatment
cycle is an aggregate maximum tolerable dose (AMTD) or a fraction
of the AMTD and wherein said AMTD and/or said fraction exceeds the
dose resulting in dose limiting toxicity (DLT) when the
immunoconjugate is administered as a single dose, including as part
of a multiple single dose regimen and/or exceeds the maximum
tolerable dose (MTD) when the immunoconjugate is administered as a
single dose, including as part of a multiple single dose regimen
within said active treatment cycle, further comprising
administering at least one cytotoxic agent, including two or three,
at least once a week or once in a treatment cycle.
27. The method of claim 26, wherein said cytotoxic agent is
lenalidomide and/or dexamethasone.
28. The method of claim 26, wherein said subject has not previously
been exposed to an immunoconjugate comprising an antibody targeting
CD138 expressing cells, to lenalidomide and/or to
dexamethasone.
29. The method of claim 26, wherein said subject has previously
been exposed to an immunoconjugate comprising an antibody targeting
CD138 expressing cells, lenalidomide and/or dexamethasone.
30. The method of claim 29, wherein said subject responded to said
exposure to an immunoconjugate comprising an antibody targeting
CD138 expressing cells, lenalidomide and/or dexamethasone.
31. The method of claim 30, wherein said target cells expressing
CD138 are refractory to exposure to an immunoconjugate comprising
an antibody targeting CD138 expressing cells, lenalidomide and/or
dexamethasone.
32. The method of claim 29, wherein said subject relapsed after
said administration.
33. The method of claim 26, wherein lenalidomide is administered at
a dose of 5 to 35 mg, or at a dose of less than 25, 20, 15 or 10
mg, orally once a day for 21 days and/or wherein dexamethasone is
administered at a dose of 20 to 50 mg, or at a dose of less than 40
or 30 mg.
34. A method for treating a disease associated with target cells
expressing CD138 comprising: administering to a subject in need
thereof an immunoconjugate comprising at least one engineered
targeting antibody targeting CD138 expressing cells, and at least
one maytansinoid, wherein said engineered targeting antibody is
functionally attached to said maytansinoid to form said
immunoconjugate, wherein at least a part of the engineered
targeting antibody confers IgG4 isotype properties, wherein the
immunoconjugate is administered in intervals of less than 11.1 days
within a period of 21 days constituting a multiple dose regimen,
wherein the aggregate dose administered within an active treatment
cycle is an aggregate maximum tolerable dose (AMTD) or a fraction
of the AMTD and wherein said AMTD and/or said fraction exceeds the
dose resulting in dose limiting toxicity (DLT) when the
immunoconjugate is administered as a single dose, including as part
of a multiple single dose regimen and/or exceeds the maximum
tolerable dose (MTD) when the immunoconjugate is administered as a
single dose, including as part of a multiple single dose regimen
within said active treatment cycle, wherein said subject suffers
from a solid tumor comprising target cells which express CD138 and
wherein said solid tumor is refractory to cancer hormone therapy or
chemotherapy or the subject has relapsed after hormone therapy or
chemotherapy, wherein said administration results in at least tumor
growth delay or tumor stasis.
35. The method of claim 34, wherein said immunoconjugate is
administered in a repeated multiple dose regime with individual
doses of 20 mg/m.sup.2 to 160 mg/m.sup.2.
36. The method of claim 34, wherein said solid tumor is estrogen
receptor negative and/or progesterone receptor negative and/or
Her2/neu negative.
37. A method for treating a disease associated with target cells
expressing CD138 comprising: administering to a subject in need
thereof an immunoconjugate comprising at least one engineered
targeting antibody targeting CD138 expressing cells, and at least
one maytansinoid, wherein said engineered targeting antibody is
functionally attached to said maytansinoid to form said
immunoconjugate, wherein at least a part of the engineered
targeting antibody confers IgG4 isotype properties, wherein the
immunoconjugate is administered in intervals of less than 11.1 days
within a period of 21 days constituting a multiple dose regimen,
wherein the aggregate dose administered within an active treatment
cycle is an aggregate maximum tolerable dose (AMTD) or a fraction
of the AMTD and wherein said AMTD and/or said fraction exceeds the
dose resulting in dose limiting toxicity (DLT) when the
immunoconjugate is administered as a single dose, including as part
of a multiple single dose regimen and/or exceeds the maximum
tolerable dose (MTD) when the immunoconjugate is administered as a
single dose, including as part of a multiple single dose regimen
within said active treatment cycle, wherein the administration of
said immunoconjugate or pharmaceutical composition comprising the
immunoconjugate is preceded by an administration of unconjugated
antibody targeting CD138 expressing cells, wherein said
immunoconjugate is administered 1-6 hours after completion of the
administration of said unconjugated antibody.
38. The method of claim 37, wherein the unconjugated antibody is
administered at a dose corresponding to a plasma level of 10 to 30
.mu.g/ml immunoconjugate in a body fluid of the subject.
39. The method of claim 38, wherein the dose administered
corresponds to about a difference between a theoretical and actual
level of said immunoconjugate in a body fluid, 0-2 hours after
completion of an administration of said immunoconjugate to said
subject.
40. The method of claim 37, wherein said antibody is administered
at a dose of 10 to 40 mg/m.sup.2 or 20-30 mg/m.sup.2.
41. The method of claim 37, wherein said immunoconjugate is
administered at an individual dose that is up to 10 mg/m.sup.2 to
30 mg/m.sup.2 lower than the dose administered without said
administration of said unconjugated antibody.
42. A method for treating a disease associated with target cells
expressing CD138 comprising: administering to a subject in need
thereof an immunoconjugate comprising at least one engineered
targeting antibody targeting CD138 expressing cells, and at least
one maytansinoid, wherein said engineered targeting antibody is
functionally attached to said maytansinoid to form said
immunoconjugate, wherein at least a part of the engineered
targeting antibody confers IgG4 isotype properties, and wherein the
immunoconjugate is administered in a multiple dose regimen
comprising three doses within 21days, being administered once a
week about 9.28 mg/m.sup.2 or 11.4 mg/m.sup.2 to about 25.7
mg/m.sup.2, or more than three doses administered more than once a
week and corresponding to a daily dose of about 9.28 mg/m.sup.2 or
11.4 mg/m.sup.2 to about 25.7 mg/m.sup.2, followed by a resting
period of about one week, which together define a treatment cycle
of at least 28 days and administering at least one cytotoxic agent,
including two or three, at least once a week or once in a treatment
cycle.
43. The method for treating a disease associated with target cells
expressing CD138 according to claim 42, wherein the immunoconjugate
is administered in three doses within 21 days, being administered
once a week and corresponding to a daily dose of about 14.28
mg/m.sup.2 to about 25.7 mg/m.sup.2.
44. The method of claim 42, wherein the immunoconjugate is
BT062.
45. The method of claim 42, wherein said cytotoxic agent is
lenalidomide and/or dexamethasone.
46. The method of claim 45, wherein lenalidomide is administered at
a dose of 5 to 35 mg, or at a dose of less than 25, 20, 15 or 10
mg, orally once a day for 21 days and/or wherein dexamethasone is
administered at a dose of 20 to 50 mg, or at a dose of less than 40
or 30 mg.
Description
FIELD OF THE INVENTION
The present invention relates to methods and treatment regimens, in
particular for human subjects, which include the administration of
immunoconjugates that are designed to target cells that express
CD138. The present invention is also directed at anticancer
combinations, pharmaceutical compositions comprising the same, and
uses thereof in the treatment of cancers that have target cells
that express CD138. The present invention is in particular directed
at anticancer combinations that show synergy or unexpected additive
effects in the treatment relative to treatments involving less than
all of the components of the combination.
BACKGROUND
CD138, which acts as a receptor for the extracellular matrix, is
overexpressed on multiple myeloma (MM) cells and has been shown to
influence MM cell development and/or proliferation. CD138 is also
expressed on cells of ovarian carcinoma, cervical cancer (Numa et
al., 2002), endometrial cancer (Choi et al., 2007), kidney
carcinoma, gall bladder, transitional cell bladder carcinoma,
gastric cancer (Wiksten et al. 2008), prostate adenocarcinoma
(Zellweger et al., 2003), mammary carcinoma (Loussouarn et al.,
2008), non small cell lung carcinoma (Shah et al., 2004), squamous
cell lung carcinoma (Toyoshima et al., 2001), colon carcinoma cells
and cells of Hodgkin's and non-Hodgkin's lymphomas, colorectal
carcinoma (Hashimoto et al., 2008), hepato-carcinoma (Li et al.,
2005), chronic lymphocytic leukemia (CLL), pancreatic (Conejo et
al., 2000), and head and neck carcinoma (Anttonen et al., 1999) to
name just a few.
The publications and other materials, including patents, used
herein to illustrate the invention and, in particular, to provide
additional details respecting the practice are incorporated herein
by reference. For convenience, the publications are referenced in
the following text by author and date and/or are listed
alphabetically by author in the appended bibliography.
Tassone et al. (2004) reported excellent binding of the murine IgG1
antibody B-B4 to the CD138 antigen expressed on the surface of MM
cells. Tassone also reported high cytotoxic activity of the
immunoconjugate B-B4-DM1, which comprises the maytansinoid DM1 as
an effector molecule, against multiple myeloma cells (see also US
Patent Publ. 20070183971).
Ikeda et al. (2008 and 2009) reported promising in vitro results
and results in xenograft models with the immunoconjugate BT062,
which is based on B-B4.
While Tassone et al. and Ikeda et al. represent contributions to
providing an effective treatment of MM and a composition of matter
that may be employed in such a treatment, there remain a number of
needs in the art.
While the use of immunoconjugates, in particular those which have
highly toxic effector molecules which are functionally attached to
a targeting agent that binds to, e.g., antigens that are not only
expressed on target cells, such as tumor cells, but also on
non-target cells which perform vital functions in the organism,
have been shown to be effective in destroying the target cells,
many failed due to their toxicity towards non-target cells. In
fact, many immunoconjugates have to be discontinued during clinical
trials because a balance between effectiveness and toxicity
(therapeutic window) could not be found: at concentrations at which
the immunoconjugate can confer benefits in terms of combating
disease, its toxicity becomes unacceptable. Thus, especially with
highly toxic effector molecules, the question often is not only
whether the targeting agent of the immunoconjugate can in fact,
bring the effector to the target and allow the effector to be
released at the target, but also if, on its way to the target
cells, the same immunoconjugate will destroy or attack an
unacceptable number of cells or organs that are pivotal to the
survival of the organism.
US Patent Publication 20110123554 discloses methods and treatment
regimens that include the administration of immunoconjugates
targeting CD138 to combat diseases, in particular in tolerable
amounts. However, while these results showed that the
immunoconjugate could be effective, while being tolerable, there is
a need for further improved treatment regimens.
There remains in particular a need to provide suitable treatment
regimens for diseases associated with CD138 expression, including
plasmaproliferative disorders associated with CD138 expression,
such as MM. There, more in particular, remains a need for treatment
regimens that ensure that toxicities towards non tumor cells, which
also express CD138 are kept to a clinically acceptable level,
either by employing only certain tolerable amounts of
immunoconjugate at levels that balance toxicities with
effectiveness to combat diseases and/or by combining the
immunoconjugate with cytotoxic agents known to be effective against
the disorder in question. There is also a need for treatment
regimens that reduce the need for medications that are used to
alleviate other symptoms of the disease and for maintenance therapy
to maintain a patient's health in a disease-free or limited-disease
state after a certain grade of disease control was achieved with
the most recent prior treatment.
This invention fulfills, in certain embodiments, one or more of
these needs as well as other needs in the art which will become
more apparent to the skilled artisan once given the following
disclosure.
SUMMARY OF THE INVENTION
The invention is directed at a method for treating a disease
associated with target cells expressing CD138, comprising:
administering to a patient in need thereof a pharmaceutical
composition an immunoconjugate and a pharmaceutically acceptable
carrier at least once a week for at least three weeks, wherein each
three week period is optionally followed by a resting period,
wherein the immunoconjugate comprises at least one targeting agent
targeting CD138 expressing cells, and at least one effector
molecule, wherein said targeting agent is functionally attached to
said effector molecule to form said immunoconjugate, and wherein
the dose of the immunoconjugate administered at least once a week
is about 20 mg/m.sup.2 to about 280 mg/m.sup.2, e.g. once a week at
a dose from about 40 mg/m.sup.2 to about 140 mg/m.sup.2, and the
pharmaceutical composition is administered for at least three weeks
alone or in combination with a cytotoxic agent.
The invention is also directed at a method for treating a disease
associated with target cells expressing CD138 comprising:
administering to a subject, in particular a human subject, in need
thereof an immunoconjugate comprising at least one engineered
targeting antibody targeting CD138 expressing cells, and at least
one effector molecule, wherein said engineered targeting antibody
is functionally attached to said effector molecule to form said
immunoconjugate, wherein preferably at least a part of the
engineered targeting antibody confers IgG4 isotype properties,
wherein the immunoconjugate is administered in a multiple dose
regimen comprising at least two doses, wherein the aggregate dose
administered within an active treatment cycle, such as an active
treatment cycle comprising 21 days, is an aggregate maximum
tolerable dose (AMTD) or a fraction of the AMTD and wherein said
AMTD and/or said fraction exceeds the dose resulting in dose
limiting toxicity (DLT) when the immunoconjugate is administered
once, preferably on day 1, within said active treatment cycle
and/or exceeds the maximum tolerable dose (MTD) when the
immunoconjugate is administered as a single dose, including a
repeated single dose.
The AMTD may exceed the dose of said DLT by at least 20% and said
MTD by at least 30%. The AMTD may be at least 240 mg/m.sup.2,
preferably 300 mg/m.sup.2, more preferably 360 mg/m.sup.2 or 420
mg/m.sup.2 and the dose resulting in said DLT may be 180 mg/m.sup.2
or 200 mg/m.sup.2. The AMTD may be at least 240 mg/m.sup.2,
preferably 300 mg/m.sup.2, more preferably 360 mg/m.sup.2 or 420
mg/m.sup.2 and said MTD may be at least 160 mg/m.sup.2 or at least
180 mg/m.sup.2.
The immunoconjugate may be administered at least three times within
21 days, preferably in equal doses.
Said multiple dose regimen may last 3 weeks and may be followed by
a resting period. During this resting period progression free
survival or stable disease may be maintained. A level of
immunoconjugate in a body fluid of a subject, during said resting
period may be at least or up to 0.5 .mu.g/ml, 1 .mu.g/ml or 2
.mu.g/ml, 3 .mu.g/ml, 4 .mu.g/ml, 5 .mu.g/ml or 6 .mu.g/ml.
The "receptor occupancy" of target cells expressing CD138, in
particular isolated target cells expressing CD138, preferably in
target cells isolated from non-solid tumors, such as myleloma cells
in bone marrow aspirates, e.g., within 24 hours, preferably within
eighteen, twelf, eight or four hours after completition of
administration of an immunconjugate according to the present
invention is, in one embodiment, more than 60%, more than 70%, more
than 75%, more than 80%, more than 85%, more than 90% or more than
95%. The "receptor occupancy" of target cells expressing CD138
prior to a subsequent administration or, respectively, more than 48
hours, more than 72 hours, more than 96 hours (4 days), more than
120 hours (5 days) or more than 144 hours (6 days) after
completition of administration is less than 70%, less than 60%,
less then 55%, less than 50%, less than 45% or less than 40%.
In one embodiment, the difference in "receptor occupancy" of target
cells expressing CD138 twentyfour, eighteen, twelf, eight or four
hours after completition of administration of the immunoconjugate
and the "receptor occupancy" of said target cells more than 48
hours, more than 72 hours, more than 96 hours (4 days), more than
120 hours (5 days) or more than 144 hours (6 days) after
completition of administration, is at least 5%, at least, 10%, at
least 15%, at least 20%, at least 25%, at least 30%, at least 35%,
at least 40%, at least 45% or at least 50%, preferably between 10%
and 50% or 20% and 40%.
In a further embodiment, the "receptor occupancy" of target cells
expressing CD138 24 hours, preferably within eighteen, twelf, eight
or four hours after completition of administration of the
immunoconjugate is high, that is, more than 60%, more than 70%,
more than 75%, more than 80%, more than 85%, more than 90% or more
than 95%, even when the immunoconjugate is administered at
realitvely low concentrations, e.g., at concentrations that
constitute less than 50%, less than 60%, less than 70%, less than
80%, but generally more than 10%, more than 20% or more an 30% of
the determined DLT of the immunoconjugate when administered once in
a 21 day treatment cycle. In yet a further embodiment, the
"receptor occupancy" of target cells expressing CD138 prior to a
subsequent administration or, respectively, more than 48 hours,
more than 72 hours, more than 96 hours (4 days), more than 120
hours (5 days) or more than 144 hours (6 days) after completition
of administration is less than 70%, less than 60%, less then 55%,
less than 50%, less than 45% or less than 40%, even when the
immunoconjugate is administered at realitvely high concentrations,
e.g., at concentrations that constitute more than 50%, more than
60%, more than 70%, more than 80% of the determined DLT of the
immunoconjugate when administered once in a 21 day treatment
cycle.
The invention is also directed at administering a total amount of
maytansinoid, in particular DM4 to a patient within 21 days of more
than 2 mg/m.sup.2, more than 3 mg/m.sup.2, more than 4 mg/m.sup.2,
more than 5 mg/m.sup.2, more than 6 mg/m.sup.2, more than 7
mg/m.sup.2, more than 8 mg/m.sup.2, more than 9 mg/m.sup.2 or more
than 10 mg/m.sup.2 preferably in accordance to any one of the
methods referred to herein.
The administering may be performed at least once a week, at
preferably equal doses for at least three weeks followed preferably
by a resting period of, e.g., one week. "Resting period" means in
this context a period after a point in time, at which, according to
the treatment schedule established for a patient, the next dose
should, but was not, administered. For example, in an
administration scheme that involves weekly administrations on days
1, 8 and 15, the resting period defines the time after day 22, when
there was no administration. In this example, this resting period
result in a treatment free interval of two weeks. The at least
three weeks followed by the resting period may define a treatment
cycle of at least 28 days, and wherein, after two or more treatment
cycles, at least stable disease may be achieved. The
immunoconjugate may, e.g., be administered every 3.sup.rd day,
every 4.sup.th day, every 5.sup.th day or every 6.sup.th day during
said three weeks period. At least stable disease may be maintained
during three, four, five, six, seven treatment cycles. After
reaching at least stable disease, the immunoconjugate may be
administered as a maintenance therapy less than three times or less
than twice within said 21 days, preferably once in said 21 days,
preferably as a repeated single dose of between 60 mg/m.sup.2 and
200 mg/m.sup.2, including about 70 mg/m.sup.2, about 80 mg/m.sup.2,
about 90 mg/m.sup.2, about 100 mg/m.sup.2, about 110 mg/m.sup.2,
about 120 mg/m.sup.2, about 130 mg/m.sup.2, about 140 mg/m.sup.2,
150 mg/m.sup.2, about 160 mg/m.sup.2, about 170 mg/m.sup.2, about
180 mg/m.sup.2, about 190 mg/m.sup.2 and about 200 mg/m.sup.2. At
least progression free survival, stable disease and or a minor
response may be obtained for more than 3 months during a
maintenance therapy.
Administration of said immunoconjugate as a repeated multiple dose
in treatment cycles lasting at least 21 days may result, after the
last administration in each cycle, in an aggregate effective amount
and a first level of the immunoconjugate in a body fluid of the
subject and wherein, when an amount equivalent to said aggregate
effective amount is administered as a single dose or repeated
single dose in said treatment cycle, it may result in a second
level of the immunoconjugate in a body fluid of said subject,
wherein the first level may be equal or below the second level,
e.g. more than 10%, more than 20% or more than 30% below the second
level.
The treatment cycle may last 21 days and/or the repeated multiple
dose may consist of 3 equal, preferably equidistant doses, more
preferably administered on days 1, 8 and 15. The aggregate
effective amount may be more than/up to 200 mg/m.sup.2, about 220
mg/m.sup.2, about 240 mg/m.sup.2, about 260 mg/m.sup.2, about 280
mg/m.sup.2, about 300 mg/m.sup.2, about 360 mg/m.sup.2 or about 420
mg/m.sup.2.
The immunoconjugate or pharmaceutical composition may be
administered for at least two 21 day treatments cycles with a one
week resting period between each treatment cycle. An administration
may be followed, after at least two 21 day treatment cycles, each
optionally followed by a resting period and/or by a further
administration of the immunoconjugate or pharmaceutical composition
as a maintenance therapy. The maintenance therapy may comprise
administering the immunoconjugate or a pharmaceutical composition
comprising the same (i) once every three to six weeks or (ii) at
repeated multiple doses, wherein each individual dose of
immunoconjugate is about 10 mg/m.sup.2, about 20 mg/m.sup.2, about
30 mg/m.sup.2, about 40 mg/m.sup.2, about 50 mg/m.sup.2, about 60
mg/m.sup.2, 70 mg/m.sup.2, about 80 mg/m.sup.2, about 90
mg/m.sup.2, about 100 mg/m.sup.2, about 110 mg/m.sup.2 or about 120
mg/m.sup.2 lower than the individual dose of a primary therapy
and/or wherein individual doses may be administered in intervals
exceeding the interval of the individual doses, e.g., by 1, 2, 3,
4, 5, 6, 7 days. Any administration of said immunoconjugate as a
multiple dose regime may result, 0-2 hours after completion of
administration, in a mean plasma level of at least 7 .mu.g/ml, 8,
9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25,
26, 27, 28, 29, 30, 40, 50, 60, 70, 80, 90 or 100 .mu.g/ml.
The methods of the invention may further include, determining 0-4
hours, including at about 1, 2, 3 or 4 hours, following an
completion of administering said immunoconjugate or a
pharmaceutical composition comprising the same, a reference level
of an said immunoconjugate or of an efficacy blood parameter in a
body fluid of a patient and determining in a subsequent
administration of said immunoconjugate, at 0-4 hours following an
completion of said subsequent administration, a subsequent level of
said immunoconjugate or efficacy blood parameter, wherein, when the
reference level is higher than the subsequent level, the aggregate
dose in a treatment cycle following said subsequent administration
may be increased by 5-100%, including 10-50% or 20-30% and/or when
the reference level is lower than the subsequent level, the
aggregate dose in a treatment cycle following said subsequent
administration may be lowered by 5-100%, including 10-50% or
20-30%.
The methods of the present invention may also further comprise
determining, 0-2 hours following an completion of administering an
individual dose of said immunoconjugate or a pharmaceutical
composition comprising the same, a level of said immunoconjugate in
a body fluid, wherein, if said level is below 7 .mu.g/ml, 8, 9, 10,
11, 12, 13, 14, 15, 16, 17, 18, 19, 20 .mu.g/ml, the individual
dose may be increased in the next treatment cycle by at least 10
mg/m.sup.2, 20 mg/m.sup.2, about 30 mg/m.sup.2, about 40
mg/m.sup.2, about 50 mg/m.sup.2, about 60 mg/m.sup.2, 70
mg/m.sup.2, about 80 mg/m.sup.2, about 90 mg/m.sup.2 or about 100
mg/m.sup.2.
The methods of the present invention may also further comprise
determining, 0-2 hours following an completion of administering an
individual dose of said immunoconjugate or a pharmaceutical
composition comprising the same, a level of an said immunoconjugate
in a body fluid, wherein, if said level is above 50 .mu.g/ml, 60,
70, 80 or 100 .mu.g/ml, the individual dose may be decreased in the
next treatment cycle by at least 10 mg/m.sup.2, 20 mg/m.sup.2,
about 30 mg/m.sup.2, about 40 mg/m.sup.2, about 50 mg/m.sup.2,
about 60 mg/m.sup.2, 70 mg/m.sup.2, about 80 mg/m.sup.2, about 90
mg/m.sup.2, about 100 mg/m.sup.2, about 110 mg/m.sup.2 or about 120
mg/m.sup.2.
In any of the methods of the present invention at least one
cytotoxic agent, including two or three, may be administered at
least once a week or once in a treatment cycle. Said cytotoxic
agent may be lenalidomide and/or dexamethasone. The said subject to
which the drug combination is administered may or may not have
previously been exposed to an immunoconjugate comprising an
antibody targeting CD138 expressing cells, to lenalidomide and/or
to dexamethasone. The subject may have responded to an exposure to
an immunoconjugate comprising an antibody targeting CD138
expressing cells, lenalidomide and/or dexamethasone. Target cells
expressing CD138 may be refractory to exposure to an
immunoconjugate comprising an antibody targeting CD138 expressing
cells, lenalidomide and/or dexamethasone. The subject may have
relapsed after said previous exposure. Lenalidomide may be
administered at a dose of 5 to 35 mg, preferably at about 25 mg, or
at a dose of less than 25, 20, 15 or 10 mg, more preferably orally
once a day in a treatment cycle of, e.g., 21 or 28 days and/or
dexamethasone may be administered at a dose of 20 to 50 mg,
preferably at about 40 mg, or at a dose of less than 40 or 30 mg,
e.g., orally once a day in a treatment cycle of, e.g., of 21 or 28
days or, e.g., on days 1-4, 9-12, 17-20 within 28 days or e.g., on
day 1, 8, 15 and 22.
The subject may suffer from a solid tumor comprising target cells
which express CD138 and said solid tumor may be refractory to
cancer hormone therapy or chemotherapy or the subject may have
relapsed after hormone therapy or chemotherapy, wherein said
administration may result in at least tumor growth delay or tumor
stasis. Said immunoconjugate may be administered in a repeated
multiple dose regime with individual doses of 20 mg/m.sup.2 to 160
mg/m.sup.2. The solid tumor may be estrogen receptor negative
and/or progesterone receptor negative and/or Her2/neu negative,
including triple negative with all of three, e.g., triple-negative
breast cancer.
An administration of said immunoconjugate or pharmaceutical
composition may also be preceded by an administration of different
targeting agent, e.g., an unconjugated antibody targeting CD138
expressing cells, wherein said immunoconjugate is administered 1-6,
preferably 2-4, hours after completion of the administration of
said unconjugated antibody. The unconjugated antibody may be
administered at a dose corresponding to a level of 10 to 30
.mu.g/ml immunoconjugate in a body fluid of the subject, in
particular a plasma level of the subject. This dose administered
may correspond to about a difference between a theoretical and
actual level of said immunoconjugate in a body fluid, 0-2 hours
after completion of an administration of said immunoconjugate to
said subject. The targeting agent may be administered at a dose of
10 to 40 mg/m.sup.2, preferably 20-30 mg/m.sup.2. As a result, the
immunoconjugate may be administered at an individual dose that is
up to 10 mg/m.sup.2, up to 20 mg/m.sup.2 or up to 30 mg/m.sup.2
lower than the dose administered without said administration of
said unconjugated antibody.
The invention is also directed at a kit comprising an antibody
against the immunoconjugate and, in a separate container,
instructions how to determine, a level of said immunoconjugate in a
body fluid obtained from said subject by addition of said antibody
to said body fluid. The kit may further comprise an immunoconjugate
comprising at least one engineered targeting antibody targeting
CD138 expressing cells, and at least one effector molecule, wherein
said engineered targeting antibody is functionally attached to said
effector molecule to form said immunoconjugate.
The engineered targeting antibody may comprise an antigen binding
region (ABR) against CD138, and a further antibody region, wherein
at least part of said further antibody region is of a human
antibody and confers said IgG4 isotype properties.
The disease may be multiple myeloma, in particular relapsed or
refractory multiple myeloma. Refractory multiple myeloma includes
"primary refractory myeloma" and "relapsed and refractory
myeloma."
Said disease expressing CD138 on target cells may be also selected
from the group consisting of renal cell carcinoma, endometrial
cancer, cervical cancer, prostate adenocarcinoma, pancreatic
carcinoma, gastric cancer, bladder cancer, mammary carcinoma,
hepato-carcinoma, colorectal carcinoma, colon carcinoma, squamous
cell carcinoma, lung cancer in particular squamous cell lung
carcinoma, non Hodgkin lymphoma, thymus, uterus, urinary or ovarian
carcinoma.
In preferred embodiments, the immunoconjugate homogenously targets
CD138 expressing target cells.
In certain embodiments, the engineered targeting antibody of the
present invention may
(i) consist essentially of antigen binding region (ABR) against
CD138 of a non-human antibody, or
(ii) comprise an antigen binding region (ABR) against CD138,
wherein said antigen binding region is of a non-human antibody,
and
a further antibody region, wherein at least part of said further
antibody region is of a human antibody.
The ABR may comprise: (a) heavy chain variable region CDR3
comprising amino acid residues 99 to 111 of SEQ ID NO: 1, and (b)
light chain variable region CDR3 comprising amino acid residues 89
to 97 of SEQ ID NO: 2, respectively.
The ABR may further comprise: (a) heavy chain variable region CDR1
and CDR2 comprising amino acid residues 31 to 35 and 51 to 68 of
SEQ ID NO: 1, and/or (b) light chain variable region CDR1 and CDR 2
comprising amino acid residues 24 to 34 and 50 to 56 of SEQ ID NO:
2, respectively.
The further antibody region may comprise: (a) amino acid residues
123 to 448 of SEQ ID NO: 1, and/or (b) amino acid residues 108 to
214 of SEQ ID NO: 2, respectively and mutations thereof that (i)
maintain or lower the antibody-dependent cytotoxicity and/or
complement-dependent cytotoxicity of the engineered targeting
antibody and/or (ii) stabilize the engineered targeting
antibody.
The antibody may comprise a light chain having at least about 70%,
more preferably 80%, 85% or 90%, sequence identity with SEQ ID No:
2 and a heavy chain having at least about 70%, more preferably 80%,
85% or 90%, sequence identity with SEQ ID No: 1, and comprising the
antigen binding regions specified above.
The effector molecule may be attached to said engineered targeting
antibody via a linker. The linker may comprise a disulfide bond.
The effector molecule (e.g., DM4) may provide sterical hindrance
between the targeting antibody and the effector molecule. The
effector molecule may be at least one maytansinoid (e.g., DM1, DM3,
or DM4), taxane, another microtubule inhibiting agent or DNA
targeting agent such as CC1065, or an analog thereof. The
immunoconjugate may bind CD138 with a targeting variation of less
than 150%, 140%, 130%, 120%, 110%, 100%, 90%, 80%, 70%, 60% or
50%.
The immunoconjugate may, in certain embodiments of the methods
disclosed herein, comprise:
a targeting agent targeting CD138 comprising
an isolated polypeptide comprising an amino acid sequence of an
immunoglobulin heavy chain or part thereof, wherein said
immunoglobulin heavy chain or part thereof has at least 70%
sequence identity with SEQ ID NO:1. A constant region of said
immunoglobulin heavy chain or said part thereof may be an IgG4
isotype constant region.
The targeting agent of the immunoconjugate may comprise a light
chain sequence having at least about 70% sequence identity with SEQ
ID NO:2. The targeting agent of the immunoconjugate may also
comprise a heavy chain sequence having at least about 70% sequence
identity with SEQ ID NO:1.
The present invention is also directed at a pharmaceutical
composition comprising any of the immunoconjugates specified herein
for the inhibition, delay and/or prevention of the growth of tumors
and/or spread of tumor cells, and one or more pharmaceutically
acceptable excipients.
The pharmaceutical composition may include cytotoxic agents as
specified herein.
The present invention is also directed at a kit comprising, in
separate containers, said pharmaceutical composition in one or more
dosage forms and, in a separate container, instructions how to
administer the one or more dosage forms to a subject, in particular
a human subject in need thereof, e.g., as repeated single dose or
other treatment regime discussed herein.
In particular, in certain embodiments, the present invention also
provides the immunoconjugate described herein for use in treating a
disease associated with target cells expressing CD138, wherein the
immunoconjugate is to be administered in the schedules and/or at
the dosages described herein. The immunoconjugate for use in this
manner can be comprised in a pharmaceutical composition. The
immunoconjugate or pharmaceutical composition may also be comprised
in a kit, where the kit further comprises the cytotoxic agent
and/or the unconjugated antibody targeting CD138, also described
herein, in separate containers. The immunoconjugate/pharmaceutical
composition and the cytotoxic agent and/or the unconjugated
antibody are to be simultaneously, separately or sequentially
administered as described herein. Similarly, the
immunoconjugate/pharmaceutical composition, the cytotoxic agent
and/or the unconjugated antibody targeting CD138 can be in the form
of a combined preparation for simultaneous, separate or sequential
use in the manner described herein.
In one aspect of the invention the administration of any of the
immunoconjugates disclosed herein is to a subject or cells of such
a subject, in particular a human subject, benefiting from such
administration. The immunoconjugate can also be used for the
manufacture of a medicament for the treatment of such a
disorder.
Use of an immunoconjugate for the manufacture of a medicament for
the treatment of a disease in a subject associated with target
cells expressing CD138, wherein the immunoconjugate comprises: (i)
at least one targeting agent targeting CD138 expressing cells, and
(ii) at least one effector molecule, optionally in combination with
one or more cytotoxic agents wherein the targeting agent is
functionally attached to the effector molecule to form the
immunoconjugate, wherein the subject does not respond (refractory
disease), or responds poorly or is relapsed from, to treatment with
one or more cytotoxic agents including immunomodulators and/or
proteasome inhibitors, and wherein the immunoconjugate is to be
administered to the subject, preferably intravenously.
A combined preparation of an immunoconjugate and an agent for
treating adverse side effects, for simultaneous, separate or
sequential use in treating a disease in a subject associated with
target cells expressing CD138, wherein the immunoconjugate
comprises: (i) at least one targeting agent targeting CD138
expressing cells, and (ii) at least one effector molecule, wherein
the targeting agent is functionally attached to the effector
molecule to form the immunoconjugate, wherein the subject does not
respond to, responds poorly to or is relapsed from, treatment with
one or more cytotoxic agents including immunomodulators and/or
proteasome inhibitors, and wherein the immunoconjugate is to be
administered to the subject, preferably intravenously, in a
pharmacokinetic equivalent of 5 mg/m.sup.2 to 140 mg/m.sup.2 of the
immunoconjugate when administered alone.
Use of an immunoconjugate and an agent for treating adverse side
effects for the manufacture of a combined preparation for
simultaneous, separate or sequential use in treating a disease in a
subject associated with target cells expressing CD138, wherein the
immunoconjugate comprises: (i) at least one targeting agent
targeting CD138 expressing cells, and (ii) at least one effector
molecule, wherein the targeting agent is functionally attached to
the effector molecule to form the immunoconjugate, wherein the
subject does not respond to, or responds poorly to or is relapsed
from, treatment with one or more cytotoxic agents including
immunomodulators and/or proteasome inhibitors, and wherein the
immunoconjugate is to be administered to the subject, preferably
intravenously, in a pharmacokinetic equivalent of 5mg/m.sup.2 to
840mg/m.sup.2 of the immunoconjugate when administered alone.
The invention is also directed at an anticancer combination
comprising at least one cytotoxic agent and at least one
immunoconjugate comprising a targeting agent targeting CD138
expressing cells, and at least one effector molecule, wherein said
targeting agent is functionally attached to said effector molecule
to form said immunoconjugate, wherein (a) the combination has a
synergy ratio of more than 1, more than 1.1, more than 1.2, more
than 1.3, more than 1.4, or (b) the combination has a synergy ratio
of about 1 and the effector molecule and the cytotoxic agent have
overlapping modes of action,
and wherein said anticancer combination is a pharmaceutical
composition or a kit comprising the at least one cytotoxic agent
and the at least one immunoconjugate in separate containers.
The cytotoxic agent may be a proteasome inhibitor, an
immunomodulatory or an anti-angiogenic agent, a DNA alkylating
agent, a histone deacetylase, or a mixture of two or more
thereof.
The cytotoxic agent may be bortezomib or carfilzomib, thalidomide,
lenalidomide or pomalidomide, melphalan or a mixture of two or more
thereof.
The effector molecule and the cytotoxic agent of the anticancer
combination may have overlapping modes of action and wherein these
modes of action involve preferably inhibition of microtubule or
induction of cell cycle arrest (melphalan, bortezomib and
lenalidomide or thalidomide are cytotoxic agents that induce cell
cycle arrest). Alternatively, they may have non-overlapping modes
of action.
If the anticancer combination is part of a pharmaceutical
composition, the pharmaceutical composition may comprise at least
one pharmaceutically acceptable excipient.
The anticancer combination may also be part of a kit in which the
at least one cytotoxic agent and the at least one immunoconjugate
are stored in separate containers.
The invention is also directed at a method for treating a disease
associated with target cells expressing CD138, comprising:
administering to a patient in need thereof an effective amount of
the anticancer combination mentioned herein or an anticancer
combination comprising at least one cytotoxic agent and at least
one immunoconjugate comprising a targeting agent targeting CD138
expressing cells and at least one effector molecule, wherein said
targeting agent is functionally attached to said effector molecule
to form said immunoconjugate, and wherein the immunoconjugate
overcomes a refractory phenotype of a patient against said
cytotoxic agent.
The invention is also directed at a method for treating a disease
associated with target cells expressing CD138, comprising:
administering to a patient in need thereof an effective amount of
an anticancer combination discussed herein and wherein the
immunoconjugate overcomes a refractory phenotype.
The invention is also directed at a method for treating a
non-plasmaproliferative disease associated with target cells
expressing CD138, comprising: administering to a subject in need
thereof or to cells affected by said non-plasmaproliferative
disease an effective amount of an immunoconjugate comprising at
least one targeting agent targeting CD138 expressing cells, and at
least one effector molecule, wherein said targeting agent is
functionally attached to said effector molecule to form said
immunoconjugate, wherein said CD138 is, in said subject, expressed
on said target cells and on non-target cells at comparable levels
or wherein said CD138 is, in said subject, expressed on said target
cells at levels below that of said non-target cells expressing
CD138.
Said non-target cells expressing CD138 may be epithelium cells.
The invention is also directed at a method for treating a
non-plasmaproliferative disease associated with target cells
expressing CD138, comprising: administering to a subject in need
thereof or to cells affected by said non-plasmaproliferative
disease an effective amount of an immunoconjugate comprising at
least one targeting agent targeting CD138 expressing cells, and at
least one effector molecule, wherein said targeting agent is
functionally attached to said effector molecule to form said
immunoconjugate, wherein the target cells of said disease shed
CD138 over a period of 24 hours, 2, 3, 4, 5, 6 days or
permanently.
Said disease may be mammary carcinoma.
A combined preparation of at least one cytotoxic agent and at least
one immunoconjugate, for
simultaneous, separate or sequential use in treating in a subject a
disease associated with target cells expressing CD138, wherein the
immunoconjugate comprises:
(i) a targeting agent targeting CD138 expressing cells, and (ii) at
least one effector molecule, wherein the targeting agent is
functionally attached to the at least one effector molecule to form
the immunoconjugate, and wherein the subject has a refractory
phenotype, relapsed after treatment or has not undergone treatment
before.
Use of at least one cytotoxic agent and at least one
immunoconjugate for the manufacture of a combined preparation for
simultaneous, separate or sequential use in treating in a subject a
disease associated with target cells expressing CD138, wherein the
immunoconjugate comprises: (i) a targeting agent targeting CD138
expressing cells and (ii) at least one effector molecule wherein
the targeting agent is functionally attached to the at least one
effector molecule to form the immunoconjugate, and wherein the
subject has a refractory phenotype, relapsed after treatment or has
not undergone treatment before.
In a preferred embodiment the combination of the at least one
cytotoxic agent and at least one immunoconjugate has a synergy
ratio of more than 1, more than 1.1, more than 1.2, more than 1.3
or more than 1.4. Alternatively, the combination of the at least
one cytotoxic agent and the at least one immunoconjugate has a
synergy ratio of about 1 and the effector molecule and the
cytotoxic agent have overlapping modes of action.
In a preferred embodiment the combination of at least one cytotoxic
agent and at least one immunoconjugate has a higher efficacy
compared to each of the agents alone. A higher efficacy is defined
by changes in efficacy blood parameters, for example M-Protein
levels, Free kappa light chain, and other relevant parameters,
which positively change relative to each single agent. In
particular, the higher efficacy can be defined by e.g. % decline in
M-Protein level, the extent of the decline in the M-Protein level,
or of the duration of the decrease in M-Protein.
An immunoconjugate for treating a non-plasmaproliferative disease
in a subject associated with target cells expressing CD138, wherein
the immunoconjugate comprises: (i) at least one targeting agent
targeting CD138 expressing cells, and (ii) at least one effector
molecule, wherein the targeting agent is functionally attached to
the effector molecule to form the immunoconjugate, and wherein in
the subject CD138 is expressed on the target cells at levels
comparable (equivalent) to or below the levels at which CD138 is
expressed on non-target cells.
Use of an immunoconjugate for the manufacture of a medicament for
treating in a subject a non-plasmaproliferative disease associated
with target cells expressing CD138, wherein the immunoconjugate
comprises: (i) at least one targeting agent targeting CD138
expressing cells, and (ii) at least one effector molecule, wherein
the targeting agent is functionally attached to the effector
molecule to form the immunoconjugate, and wherein in the subject
CD138 is expressed on the target cells at levels comparable
(equivalent) to or below the levels at which CD138 is expressed on
non-target cells.
The invention is also directed at a method for treating a
non-plasmaproliferative disease associated with target cells
expressing CD138, comprising: administering to a subject in need
thereof or to cells of said non-plasmaproliferative disease an
effective amount of an immunoconjugate comprising at least one
targeting agent targeting CD138 expressing cells, and at least one
effector molecule, wherein said targeting agent is functionally
attached to said effector molecule to form said immunoconjugate,
wherein immunoconjugate induces at least tumor stasis, preferably
remission of a solid tumor.
This remission may be a remission followed by a time interval which
is free of re-growth of said tumor (complete remission). This time
interval may be more than 1, 2, 3, 4, 5, 6, 7, 8, 9, 10 weeks, half
a year or 1 year or more.
The solid tumor may be a pancreatic carcinoma or a mammary
carcinoma.
The disease may renal cell carcinoma, endometrial cancer, cervical
cancer, prostate adenocarcinoma, pancreatic carcinoma, gastric
cancer, bladder cancer, mammary carcinoma, hepato-carcinoma,
colorectal carcinoma, colon carcinoma, squamous cell carcinoma,
lung cancer in particular squamous cell lung carcinoma, non Hodgkin
lymphoma, thymus, uterus, urinary or ovarian carcinoma, both in
form of primary tumors as well as metastatic tumors derived from
primary tumors.
The solid tumor may be a mammary carcinoma, which are estrogen
receptor negative and/or progesterone receptor negative and/or
Her2/neu negative. A solid tumor according to the present invention
may also be a mammary carcinoma, which does not or poorly respond
to taxane therapy or is hormone refractory.
The receptor occupancy at target cells, such as bone marrow cells,
may be more than 70%, more than 80%, more than 90% or more than
75%, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, 11 or 12 hours after
completition of an administration of the immunoconjugate.
BRIEF DESCRIPTION OF THE FIGURES
FIG. 1 provides a schematic representation of nBT062 having
effector molecules attached.
FIG. 2 is a chemical representation of BT062.
FIG. 3 shows the conversion of ansamitocin P-3 to maytansinol
(stereochemistry is omitted for simplicity).
FIG. 4 shows a representative synthesis scheme of DM4.
FIG. 5 is a schematic representation of an antibody conjugation
(nBT062 to DM4).
FIG. 6 shows an analysis of the binding of nBT062-SPDB-DM4,
nBT062-SPP-DM1, nBT062-SMCC-DM1 and nBT062 antibody to OPM-2 cells.
Different concentrations of nBT062 and conjugates were given to the
cells and mean fluorescence was measured by FACS analysis.
FIG. 7(A)-(D) depict in vitro cytotoxicity of nBT062-DMx conjugates
towards MOLP-8 (CD138.sup.+) and BJAB (CD138.sup.-) cells. The
cells were cultured in flat bottom plates and incubated with the
indicated concentrations of immunoconjugates for 5 days. WST
reagent was added for further 3 hours to assess cell viability. In
(D) cytotoxic activity of nBT062-SPDB-DM4 was analyzed in the
presence or absence of blocking antibody (1 .mu.M nBT062).
FIG. 8 shows the complete remission of a xenograft pancreas
carcinoma in mice treated with BT062 vs. a control. Complete
remission is maintained: in the treatment free observation period,
no tumor re-growth was observed.
FIG. 9 shows the complete remission of a xenograft mammary
carcinoma in mice treated with BT062 vs. a control. Complete
remission is maintained, since in the treatment free observation
period, no tumor re-growth was observed.
FIG. 10 shows the complete remission of a xenograft mammary
carcinoma in mice treated with 2 mg/kg or 4 mg/kg BT062 (once
weekly) vs. a control or Taxane. At 1 mg/kg BT-062 once weekly,
tumor stasis is achieved. This is defined as the minimal effective
dose.
FIG. 11 shows the complete remission of a xenograft primary lung
adenocarcinoma in mice treated with 4 mg/kg and 23.85 mg/kg BT062
(once weekly) vs. a vehicle control.
FIG. 12 shows the complete remission of a xenograft bladder
(transitional cell) carcinoma (metastatic sample) in mice treated
with 4 mg/kg and 23.85 mg/kg BT062 (once weekly) vs. a vehicle
control.
FIG. 13 illustrates the rapid plasma clearance for dosages ranging
from 40 mg/m.sup.2 to 120 mg/m.sup.2, while higher doses as
illustrated here by a dose of 160 mg/m.sup.2, showed plasma
clearance closer to the expected value.
FIG. 14 shows the measured Cmax values of BT062 compared to the
theoretical Cmax values.
FIGS. 15 and 16 show that the Cmax values are generally similar
over several treatment cycles in a repeated single dose regime as
indicated.
FIG. 17 clarifies that the rapid plasma clearance cannot be
attributed to a buffering effect caused by soluble CD138.
FIG. 18 depicts the progression free survival for human subjects
treated with different dosages of BT062 administered in the course
of the indicated treatment cycles, wherein each active treatment
cycle lasted 21 days and the respective dosage was administered on
days 1, 8 and 15 of each cycle. Each cycle of 21 days was followed
by a 7 day resting period (28 indicate the 21+7 days, per
"cycle")
As can be seen 14 patients were on study treatment for more than 3
months. For two of these patients progression free survival of at
least 300 days (about 10 months) has been reported.
FIG. 19 shows in (A) the course of Cmax values with different
dosages administered weekly for three weeks followed by a week long
resting period and in (B) the Cmax values, 0-2 hours after
completion of the administration, for different doses. The
theoretical Cmax values are also shown.
FIG. 20 shows the level of serum M-protein measured for a patient
receiving 50 mg/m.sup.2 weekly for three weeks, followed by a 7 day
resting period. Days -111 to 169 are shown. Arrows indicate
treatment with BT062.
FIG. 21 shows the level of lambda-kappa FLC (strong increase before
first treatment, strong decrease from day 1 to 57) measured for a
patient (oligo-secretory multiple myeloma) receiving 65 mg/m.sup.2
weekly for three weeks, followed by a 7 day resting period. Days
-83 to 163 are shown.
FIG. 22 shows the level of lambda-kappa FLC (strong increase before
first treatment, stabilization for two cycles) measured for a
patient (oligo-secretory multiple myeloma) receiving 80 mg/m.sup.2
weekly for three weeks, followed by a 7 day resting period. Days
-111 to 85 are shown.
FIG. 23 shows the level of lambda-kappa FLC (decrease for three
months) measured for a patient (oligo-secretory multiple myeloma)
receiving 100 mg/m.sup.2 weekly for three weeks, followed by a 7
day resting period. Days -83 to 141 are shown.
FIG. 24 shows the level of urine M-protein measured for a patient
receiving 3.times.120 mg/m.sup.2 weekly for three weeks, followed
by a 7 day resting period. Days -27 to 337 are shown.
FIG. 25 shows the level of serum M-protein measured for a patient
receiving 3.times.160 mg/m.sup.2 weekly for three weeks, followed
by a 7 day resting period. Days -20 to 57 are shown, which indicate
a minor response.
FIG. 26 shows the level of kappa FLC measured for a patient
receiving 160 mg/m.sup.2 at three weeks intervals. Days -21 to 101
are shown.
FIG. 27 shows a comparison of plasma levels of BT062 administered
as a repeated single dose of 160 mg/m.sup.2 in comparison to a
multiple dose of 100 mg/m.sup.2 and 120 mg/m.sup.2 administered
three times in an active treatment cycle of equal length (21
days).
FIG. 28 shows serum M-protein levels during an extended
administration of BT062 as repeated single doses BT062 of 160
mg/m.sup.2, which lead to minor response with manageable side
effects.
FIG. 29 shows serum M protein levels and Cmax values over time in a
repeated single dose administration for a patient treated with a
repeated single dose of BT062 of 160 mg/m.sup.2 (see also FIG.
28).
FIG. 30 shows the effect of the combination therapy on median tumor
volume (TV) in a xenograft mouse model (MOLP-8 MM xenograph model).
The results show the effects of the combination of BT062 and
lenalidomide.
FIG. 31 shows the effect of the combination therapy on median tumor
volume (TV) in a xenograft mouse model. The result shows the
effects of the combination of BT062 and VELCADE.
FIG. 32 shows the effect of lenalidomide on different CD138
expressing cells in vitro, in particular MOLP-A cells (A), RPMI8226
cells (B), NCI-H929 cells (C) and U266 cells (D). Notably CD138
expression was not affected in vivo (L363 MM xenograft model) by
the treatment of the combination of lenalidomide and dexamethasone
(data not shown).
FIG. 33 shows the results of an in vivo (L363 MM xenograft model)
drug combination study wherein BT062 (2 mg/kg, 4 mg/kg) was
administered intravenously on days 1, 8, 15, 22 and 29;
lenalidomide was administered orally on days 0-4, 7-11, 14-18,
21-25, 28-32 and dexamethasone was administered subcutaneously on
days 0, 7, 14, 21 and 28. A considerable reduction in tumor volume
relative to the simple combination of lenalidomide and
dexamethasone can in particular be seen in the context of the 4
mg/kg BT062 dosage scheme. The results are shown in terms of the
effect on the median relative tumor volume in the model relative to
an intravenous administration of a vehicle control. The median
relative tumor volume on day X was, here and in the subsequent
figures calculated as follows: The relative volumes of individual
tumors (Individual RTVs) for Day X were calculated by dividing the
individual tumor volume on Day X (Tx) by the individual volume of
the same tumor on Day 0 (T0) multiplied by 100%. Group tumor
volumes were expressed as the median or mean (geometric) RTV of all
tumors in a group (group median/mean RTV).
FIG. 34 shows the level of serum M-protein measured for a patient
scheduled to receive 80 mg/m.sup.2 of BT062 weekly for three weeks,
followed by a 7 day resting period. BT062 was administered in
combination with Lenalidomide and Dexamethasone. Days -13 to 106
are shown, which indicate a minor response.
FIG. 35 shows the results of an in vivo (human derived breast
cancer model in NMRI nude mice) study wherein BT062 (0.5 mg/kg, 1
mg/kg, 2 mg/kg, 4 mg/kg) was administered intravenously on days 0,
7, 14, 21, 28 and 35 and taxol (10 mg/kg) was administered
intravenously on days 1, 8, 15 and 22. BT062 showed at higher
concentrations superior results. The results are shown in terms of
the effect on the mean relative tumor volume in the model relative
to an intravenous administration of PBS. For the calculation of the
median relative tumor volume on day, see FIG. 33.
FIG. 36 shows the results of an in vivo (human derived breast
cancer model with CD138 IHC score 2-3 in NMRI nude mice) study
wherein BT062 (1 mg/kg, 2 mg/kg, 4 mg/kg, 8 mg/kg) was administered
intravenously on days 0, 7, 14, 21, 28 and 35 and Docetaxel (10
mg/kg) was administered intravenously on days 0, 7 and 14. BT062
showed at higher concentrations superior results. Docetaxel was as
effective as the highest concentration of BT062. The results are
shown in terms of the effect on the mean relative tumor volume in
the model relative to an intravenous administration of PBS. For the
calculation of the median relative tumor volume on day, see FIG.
33.
FIG. 37 shows the results of an in vivo (human derived breast
cancer model with CD138 IHC score 1-2 in NMRI nude mice) study
wherein BT062 (1 mg/kg, 2 mg/kg, 3 mg/kg, 4 mg/kg) was administered
intravenously on days 0, 7, 14, 21, 28 and 35 and Docetaxel (10
mg/kg) was administered intravenously on days 0, 7 and 14. No
difference in the treatment regimens was observed. The results are
shown in terms of the effect on the mean relative tumor volume in
the model relative to an intravenous administration of PBS. For the
calculation of the median relative tumor volume on day, see FIG.
33.
FIG. 38 shows the results of an in vivo (human derived prostate
cancer model in NMRI nude mice) study wherein BT062 (1 mg/kg, 2
mg/kg, 4 mg/kg, 8 mg/kg) was administered intravenously on days 0,
7, 14, 21, 28 and 35 and Docetaxel (10 mg/kg) was administered
intravenously on days 0, 7 and 14. BT062 showed at higher
concentrations superior results. The results are shown in terms of
the effect on the mean relative tumor volume.
Docetaxel was as effective as the highest concentration of BT062
and allowed for maintenance of the low tumor volume over time.
DETAILED DESCRIPTION OF VARIOUS AND PREFERRED EMBODIMENTS OF THE
INVENTION
The present invention relates to the administration to subjects, in
particular human subjects (patients), in need thereof, of
immunoconjugates comprising CD138 targeting agents described herein
and the delivery of the effector molecule(s) of the
immunoconjugates to target sites and the release of effector(s)
molecule in or at the target site, in particular target cells,
tissues and/or organs. More particularly, the present invention
relates to immunoconjugates comprising such CD138 targeting agents
and potent effector molecules that are attached to the targeting
agents. The effector molecules may be activated by cleavage and/or
dissociation from the targeting agent portion of the
immunoconjugate in or at a target site. The immunoconjugates may be
administered alone or as part of an anticancer combination that
includes a cytotoxic agent such as, but not limited to, a
proteasome inhibitor (e.g., bortezomib, carfilzomib),
immunomodulatory agent/anti-angiogenic agent (e.g., thalidomide,
lenalidomide or pomalidomide), DNA alkylating agent (e.g.,
melphalan) or corticosteroid (e.g., dexamethasone), wherein the
anticancer combination has synergistic effects or unexpected
additive effects in the treatment of cancer over the
immunoconjugate used alone in monotherapy, the cytotoxic agent used
alone in monotherapy or both.
The immunoconjugates according to the present invention may be
administered to a subject in need of treatment or to cells isolated
from such a subject in need of treatment. The effector molecule or
molecules may be released from the immunoconjugate by
cleavage/dissociation in or at a target cell, tissue and/or
organ.
In one example, the immunoconjugate BT062, which targets CD138
expressing cells via the nBT062 antibody and comprises DM4 as an
effector molecule, was administered to a patient with
relapsed/refractory multiple myeloma 14 times in an amount of 40
mg/m.sup.2 as in a repeated multiple dose regime, wherein the
length of each active treatment cycle was 21 days with three
doses/per cycle being administered on days, 1, 8, and 15 of the
cycle and an resting period of one week was inserted before the
next active treatment cycle was started. Expressed differently, the
treatment cycle was 28 days with three doses/per cycle being
administered on days, 1, 8, and 15 of the cycle and none
administered on day 22, resulting, in this example, in a treatment
free period of about two weeks. In this example, the
immunoconjugate was administered intravenously to the patient so
that it could better concentrate in and/or at tumor cells.
Measurements of the plasma concentration of BT062 showed that in an
initial measurement phase (up to 2 hours after the end of
administration) Cmax values for BT062 were significantly below the
theoretically calculated value while no DLTs (dose limiting
toxicities) were observed, suggesting that BT062 concentrates at
the tumor target rather than randomly attaching to target and
non-target CD138. A "buffer effect" resulting from sCD138 (soluble
CD138) could be excluded (compare FIG. 17). As will be discussed
below in the context of administrations at 80 mg/m.sup.2, a rapid
concentration at the target cells could be confirmed.
An active treatment cycle is a treatment cycle that is defined by a
regular administration of the active agent, here generally the
immunoconjugate, and excludes any resting periods. An active
treatment cycle includes typically three weeks of active treatment
and is considered to end not with the last dose administered, but
at the time when a further administration would be due. Thus an
active treatment cycle including a dose of 120 mg/m.sup.2 on day 1,
65 mg/m.sup.2 on both days 8 and 15, would be considered to end on
day 21 and to be 21 days long. While an active treatment cycle
generally lasts 21 days, it may range from at least two weeks (14
days) to four weeks (28 days). In the latter case an active
treatment cycle and a "full" or "complete" treatment cycle are the
same. Within the period of an active treatment cycle, the active
agent, is regularly administered. This includes, e.g., in
alternating 2 and 3 day intervals, in 4 day intervals, in
progressive increasing intervals such as on day 1, 3, 6, 10, 15. A
treatment cycle may in addition to the active treatment further
comprise a resting period. E.g. in the example above, the above
administration scheme in a treatment cycle of 28 days would be
considered to comprise no administration of day 22. Such a
treatment cycle, including a resting period, is also referred to
herein as "full" or "complete" treatment cycle. A treatment free
period describes the time during which no treatment is given. Thus,
in the above example, the treatment free period would start at day
16. At the beginning of the resting period, no immunoconjugate is
administered to the patient. In a preferred embodiment no treatment
of any sort is administered during this period. The resting period
may lasts, e.g., 5, 6, 7, 8, 9, 10, 11, 12, 13, 14 days or more
typical is one week. A treatment free period may last 14, 15, 16,
17, 18, 19, 20, 21 days or more.
In another example, the immunoconjugate BT062 was administered to a
patient with relapsed/refractory multiple myeloma 18 times in an
amount of 50 mg/m.sup.2 each as repeated multiple doses, wherein
the length of each treatment cycle was 21 days with three doses/per
cycle being administered on days, 1, 8, and 15 of the cycle and an
resting period of one week was inserted before the next treatment
cycle was started. Expressed differently, the treatment cycle was
28 days with three doses/per cycle being administered on days, 1,
8, and 15 of the cycle and none administered on day 22. In this
example, the immunoconjugate was administered intravenously to the
patient so that it could better concentrate in and/or at tumor
cells. No additional means were provided to release the effector
molecule from the immunoconjugate. Six treatment cycles were well
tolerated and at least stable disease could be achieved over six
cycles, with a decrease of serum M-protein by nearly 25% during
after the 3.sup.rd and 5th treatment cycle (FIG. 20).
In yet another example, the immunoconjugate BT062 was administered
to a patient with relapsed/refractory multiple myeloma 19 times in
an amount of 65 mg/m.sup.2 as repeated multiple doses, wherein the
length of each treatment cycle was 28 days with three doses/per
cycle being administered on days, 1, 8, and 15 of the cycle and
none administered on day 22. The treatment free period was thus 14
days before the next treatment cycle started. At this concentration
plasma levels were still below the theoretical Cmax (mean
percentage from theoretical Cmax=60%; Table 11a), but not to the
degree observed with lower doses, e.g., 40 mg/m.sup.2 or 50
mg/m.sup.2 (mean percentage from theoretical Cmax=33% Table 11a).
However, a strong decrease of the serum FLC level could be observed
after just a single treatment cycle and could be maintained for two
months (FIG. 21). Besides the higher percentage from theoretical
Cmax reached at does level of 65 mg/m.sup.2, the total plasma
concentration missing to the theoretical Cmax (here mean total 17.7
mg/m.sup.2, Table 11b) was similar to the one ones observed at
lower concentrations of 40 mg/m.sup.2 or 50 mg/m.sup.2 (mean total
18.6 mg/m.sup.2 and 23.0 mg/m.sup.2, Table 11b). Thus, the total
plasma concentrations missing to the theoretical Cmax may stay at
different concentrations, despite an increase of the mean
percentage from the theoretical Cmax by more than 10% more than 20%
or more than 25%, preferably between 15 and 25%, stayed within the
range of 15-25 mg/m.sup.2, namely around 20 mg/m.sup.2. For 14
patients (out of 32 on the study) progression free survival of at
least 3 months has been reported (FIG. 18), for four of these
patients progression free survival of at least 168 days has been
reported. One of these four patients showed clear reduction of
serum M protein after 9 treatments (Patient No. 6, please see also
FIG. 20) and for another patient a strong decrease in FLC could be
observed within the first 2 months (Patient No. 19, see also FIG.
24). The first DLT was observed in the 140 mg/m.sup.2 cohort
(Patient No. 23), but no DLT was reported for the six other
patients at this dose level. For two out of the four patients
(Patient Nos. 30 and 32) that were treated with weekly doses of 160
mg/m.sup.2 DLT was observed and prompted a reduction of the dose to
of 140 mg/m.sup.2 in subsequent cycles.
In yet another example, the immunoconjugate BT062 was administered
to a patient with non-secretory relapsed/refractory multiple
myeloma (Patient No. 12 in FIG. 18) for 15 cycles in an amount of
80 mg/m.sup.2 as repeated multiple doses, wherein the length of
each treatment cycle was 28 days with three doses/per cycle being
administered on day 1, 8, and 15 of the cycle and none administered
on day 22. In this example, the immunoconjugate was administered
intravenously to the patient so that it could better concentrate in
and/or at tumor cells. At this concentration plasma levels were
still below the theoretical Cmax, but not to the degree observed
with lower doses, e.g. 40 mg/m.sup.2 (mean percentage from
theoretical Cmax-33%; Table 11a). After three administrations at 80
mg/m.sup.2, totaling an administration of 240 mg/m.sup.2 (aggregate
dose) within three weeks, the immunoconjugate remained well
tolerated. A rapid concentration at the tumor target could be
confirmed at this dosage. Table 12 shows the results of receptor
occupancy (RO) measurements. Here the binding of BT062 to the
receptor (CD138) was measured on multiple myeloma cells in the bone
marrow, ergo the site of the tumor, in the Multiple Myeloma
patient. Receptor (CD138) bound BT062 was stained with anti-May
antibodies (Sample 1). Total CD138 was measured with anti-May
antibodies after receptor saturation with BT062 (Sample 2).
Incubation with an IgG1 isotype determined unspecific binding to
the sample (Sample 3). The first row in Table 12 shows the results
of a measurement within four hours after completition of the
administration. As can be seen, the receptor occupancy within 4
hours after end of administration is, in this case, 99%. The
patient showed a partial response. The duration of an
administration (administration time) obviously differs with the
mode of administration.
Administration times in intravenous (IV) administrations are
generally defined by mg/min (1 mg/min for first 15 min and if
tolerated 3 mg/min for the rest) and therefore increase with the
dose levels assigned to the patient. The times for flushing the
administration line after administration vary as well. In the
present study, for doses between 10 mg/m.sup.2 and 200 mg/m.sup.2,
the shortest infusion time was 18 minutes and maximum infusion time
was 3 hours and 2 minutes with a mean of 1 hour and 36 min. If 200
mg/m.sup.2 are administered completely at 1 mg/min this could
result in an administration up to 8 hours. In an alternative
embodiment, the immunoconjugate may be administered as IV bolus
within a minute.
Thus, an administration according to the present invention is
"completed" any time between 0 and 8 hours after start of an
administration, generally within 0 and 4, often within 2 hours from
the start of an administration.
FIG. 22 shows a patient (13 in FIG. 18) subjected to the same
administration scheme (80 mg/m.sup.2 as repeated multiple doses,
wherein the length of each treatment cycle was 28 days with three
doses/per cycle being administered on day 1, 8, and 15 of the cycle
and none administered on day 22) which was administered to a
relapsed/refractory patient. The strong increase of lambda-kappa
before the first treatment day could be stabilized for 2
cycles.
Patient 12 in FIG. 18 (80 mg/m.sup.2 as repeated multiple doses as
above), showed a partial response for about 8 months.
In a further example, the immunoconjugate BT062 was administered to
a patient with relapsed/refractory multiple myeloma six times in an
amount of 100 mg/m.sup.2 as repeated multiple doses, wherein the
length of each active treatment cycle was 21 days with three
doses/per cycle being administered on day 1, 8, and 15 and a
resting period of 1 week (no administration at day 22 leading
effectively to a two weeks break of administration). In this
example, the immunoconjugate was administered intravenously to the
patient so that it could better concentrate in and/or at tumor
cells.
FIG. 23 shows the result of this dosage scheme with patient 15
(FIG. 18, relapsed refractory with oligo-secretory MM), who showed
progression free survival for more than 3 months.
At this concentration plasma level was only below the theoretical
Cmax during the first two administrations (Table 11a) pointing
towards an accumulation of the immunoconjugate after weekly dosing
at this dose. However, in the equivalent experiments with 120
mg/m.sup.2 as repeated multiple dose, these values went down,
indicating that the 100 mg/m.sup.2 outcomes might be a deviation in
a single patient and also indicating that at even higher dosages no
significant accumulation might take place. After three
administrations at 100 mg/m.sup.2, at 120 mg/m.sup.2 and, for the
most part, at 140 mg/m.sup.2 and totaling an administration of 300
mg/m.sup.2, 360 mg/m.sup.2 and 420 mg/m.sup.2, respectively within
three weeks, the immunoconjugate remained well tolerated. No DLTs
were observed after three 21 day cycles of 3.times.100 mg/m.sup.2
(300 mg/m.sup.2) or 3.times.120 mg/m.sup.2 (360 mg/m.sup.2) in each
cycle (3.times.300 mg/m.sup.2=900 mg/m.sup.2 in 12 weeks and
3.times.360 mg/m.sup.2=1080 mg/m.sup.2 in 12 weeks) compared to 640
mg/m.sup.2 (four 21 day cycles of 160 mg/m.sup.2 each).
In a further example, the immunoconjugate BT062 was administered to
a patient with relapsed/refractory multiple myeloma six times in an
amount of 120 mg/m.sup.2 as repeated multiple doses, wherein the
length of each active treatment cycle was 21 days with three
doses/per cycle being administered on day 1, 8, and 15 and a
resting period of 1 week. In this example, the immunoconjugate was
administered intravenously to the patient so that it could better
concentrate in and/or at tumor cells.
FIG. 24 shows the result of this dosage scheme with patient 19
(FIG. 18, relapsed refractory with oligo-secretory MM), who showed
an unconfirmed minor response, despite a number of a number of
treatment delays (x).
At this concentration the plasma level was still below the
theoretical Cmax (Table 11a) indicating no relevant accumulation of
the immunoconjugate after weekly dosing at this dose. After three
administrations at 120 mg/m.sup.2, totaling an administration of
360 mg/m.sup.2 within three weeks, the immunoconjugate remained
well tolerated. No DLTs were observed after three 21 day cycles of
3.times.120 mg/m.sup.2 (360 mg/m.sup.2) in each cycle.
In a further example, the immunoconjugate BT062 was administered to
a patient with relapsed/refractory multiple myeloma seven times in
an amount of 160 mg/m.sup.2 as repeated multiple doses, wherein the
length of each active treatment cycle was 21 days with three
doses/per cycle being administered on day 1, 8, and 15 and a
resting period of 1 week. In this example, the immunoconjugate was
administered intravenously to the patient so that it could better
concentrate in and/or at tumor cells. FIG. 25 shows the results
(M-protein decreased by more than 25% qualifying for minor
response) for patient 31, which as can be seen from FIG. 18 did not
display DLT at this concentration.
As indicated in FIG. 18, 2 out of 4 patients displayed DLTs at 160
mg/m.sup.2 (elevated liver enzymes, neutropenia) but could resume
treatment at 160 mg/m.sup.2. In this administration scheme, MAD was
160 mg/m.sup.2, while 140 mg/m.sup.2 was determined to be the MTD
(1 out of 6 patients displayed DLT at this concentration)
TABLE-US-00001 TABLE 1 Total amount of BT062 delivered within 3
weeks results in different tolerability of the drug. A single dose
of 200 mg/m.sup.2 in a 3 week period resulted in DLTs (target
related toxicities). Similar total doses (3 .times. 80 mg/m.sup.2,
3 .times. 100 mg/m.sup.2, 3 .times. 120 mg/m.sup.2, 3 .times. 140
mg/m.sup.2) administered in 3 intervals during a 3 week period did
not result in any serious drug related toxicities in patients.
Single dose every Single dose every three weeks three weeks
Repeated single dose 160 200 240, 300, 360, 420 Drug-related
adverse DLTs No serious drug-related events such as eye toxicities
(up to now), one toxicity DLT (palmar-plantar erythrodysaethesia
syndrome) at 420 out of six
In yet another example, the immunoconjugate BT062 was
co-administered to a patient with relapsed multiple myeloma for
four cycles in an amount of 80 mg/m.sup.2 as repeated multiple
doses, wherein the length of each treatment cycle is 28 days with
three doses/per cycle being administered on days, 1, 8, and 15 of
the cycle and none administered on day 22. At the same time a 25 mg
daily oral dose of lenalidomide is administered at 1 to 21 and 40
mg of dexamethasone is administered weekly (days 1, 8, 15, 22). In
this example, the immunoconjugate is administered intravenously to
the patient so that it can better concentrate in and/or at tumor
cells. Despite delayed start of treatment cycle 2 and 3 and
skipping the dose of BT062 at day 15 of Cycle 3 and lenalidomide on
day 15 to 21 in cycle 3, a minor response achieved after the first
cycle was maintained (FIG. 34).
In another example, the immunoconjugate BT062 is co-administered to
a patient suffering from a pancreatic tumor as repeated multiple
dose of 220 mg/m.sup.2, as solid tumors trap immunoconjugate more
quickly than malignancies not associated with solid masses wherein
the length of each treatment cycle is 28 days with three doses/per
cycle being administered on days 1, 8, and 15 of the cycle and none
administered on day 22. At the same time a 10 mg daily oral dose of
the Immunomodulatory agent lenalidomide is administered. In this
example, the immunoconjugate is administered intravenously to the
patient so that it could better concentrate in and/or at tumor
cells. The administration is followed by a maintenance treatment
consisting of a repeated single dose of 160 mg/m.sup.2 of the
immunoconjugate at day 1 of a 21 day cycle for 4 months.
CD138 or syndecan-1 (also described as SYND1; SYNDECAN; SDC; SCD1;
CD138 ANTIGEN, SwissProt accession number: P18827 human) is a
membrane glycoprotein that was originally described to be present
on cells of epithelial origin, and subsequently found on
hematopoietic cells (Sanderson, 1989). CD138 has a long
extracellular domain that binds to soluble molecules (e.g., the
growth factors EGF, FGF, HGF) and to insoluble molecules (e.g., to
the extracellular matrix components collagen and fibronectin)
through heparan sulfate chains (Langford, 1998; Yang, 2007) and
acts as a receptor for the extracellular matrix. CD138 also
mediates cell to cell adhesion through heparin-binding molecules
expressed by adherent cells. It has been shown that CD138 has a
role as a co-receptor for growth factors of myeloma cells (Bisping,
2006). Studies of plasma cell differentiation showed that CD138
must also be considered as a differentiation antigen (Bataille,
2006).
In malignant hematopoiesis, CD138 is highly expressed on the
majority of MM cells, ovarian carcinoma, kidney carcinoma, gall
bladder carcinoma, breast carcinoma, prostate cancer, lung cancer,
colon carcinoma cells and cells of Hodgkin's and non-Hodgkin's
lymphomas, chronic lymphocytic leukemia (CLL) (Horvathova, 1995),
acute lymphoblastic leukemia (ALL), acute myeloblastic leukemia
(AML) (Seftalioglu, 2003 (a); Seftalioglu, 2003 (b)), solid tissue
sarcomas, colon carcinomas as well as other hematologic
malignancies and solid tumors that express CD138 (Carbone et al.,
1999; Sebestyen et al., 1999; Han et al., 2004; Charnaux et al.,
2004; O'Connell et al., 2004; Orosz and Kopper, 2001). Expression
of CD138 is also associated with different types of
gastrointestinal malignancies (Conejo et al., 2000). As shown in
Table 2, a number of tumorgenic cell lines exist which are
associated with CD138 expression/overexpression.
TABLE-US-00002 TABLE 2 CD138 expression on different cell lines. In
the context of MM it was shown that the sensitivity towards BT062
correlates with a higher expression of CD138 (RFI = relative
fluorescence index). Sensitivity CD138 Expression cell line Origin
IC.sub.50 (nM) RFI* receptors/cell NCI-H929 MM 0.38 502 788,752
PC-3 prostate cancer 0.79 541 195,671 U266 MM 1.59 617 782,987
MOLP-2 MM 1.78 425 161,064 SK-BR-3 breast carcinoma 2.72 485
444,350 LNCaP postate cancer 7.39 179 23,388 CAPAN-2 pancreas 15.51
328 n.d. carcinoma PANC-1 pancreas 36.38 34 18,085 carcinoma T47D
breast carcinoma 89.28 217 42,264 Jurkat T cell lymphoma 39.00 n.d.
0
The observed sensitivity of, e.g., the breast carcinoma cell lines
and pancreas carcinoma cell lines was substantially lower than that
of that of the MM cell lines. Nonetheless, as described in the
experimental section in xenograft mouse models using cells from
patients with breast cancer and pancreatic cancer, not only
comparable, but significantly better results than in comparable
xenograft models for MM were obtained. In both instances complete
remission could eventually be obtained, while comparable MM models
showed marked delay in tumor growth, but not complete
remission.
While in pancreatic cancer there appears to be no difference in
syndecan-1 mRNA expression between early and advanced tumors, in
mammary carcinoma, it was reported that CD138 can be lost over time
as reflected by weak or lacking IHC staining. CD138 loss of
expression had been reported and was often correlated with a shift
of expression, i.e., de novo expression on surrounding stroma
(Loussouarn, 2008). As a result, fewer targets for CD138 targeting
agents can be expected over time.
Other cancers that have been shown to be positive for CD138
expression are many ovarian adenocarcinomas, transitional cell
bladder carcinomas, kidney clear cell carcinomas, squamous cell
lung carcinomas; and uterine cancers (see, for example, Davies et
al., 2004; Barbareschi et al., 2003; Mennerich et al., 2004;
Anttonen et al., 2001; Wijdenes, 2002).
The treatment of active (symptomatic) multiple myeloma and related
plasmaproliferative disorders shall serve as an example of diseases
that can be treated via immunoconjugates of the present
invention.
Plasmaproliferative disorder as used herein means plasma cell
and/or hematologic disorders such as MGUS, SMM, active
(symptomatic) MM, Waldenstrom's Macroglobulinemia, solitary
plasmacytoma, systemic AL amyloidosis and POEMS syndrome.
Multiple myeloma (MM) refers to a malignant proliferation of plasma
cells that typically originates in bone marrow, involves chiefly
the skeleton of a patient, and presents clinical features
attributable to the particular sites of involvement and
abnormalities in formation of plasma proteins. The condition is
usually characterized by numerous diffuse foci or nodular
accumulations of abnormal or malignant plasma cells in the marrow
of various bones (especially the skull), causing palpable swellings
of the bones, and occasionally in extraskeletal sites. Upon
radiological exam, the bone lesions may have a characteristic
"punched out" appearance. The cells involved in the myeloma
typically produce abnormal proteins and/or abnormal protein levels
in the serum and urine. The disease typically develops from
monoclonal gammopathy of undetermined significance (MGUS) to
smoldering multiple myeloma (SMM) to active multiple myeloma (MM).
Symptoms of these conditions vary, but may include hypercalcemia,
renal insufficiency, fatigue, anemia, bone pain, spontaneous
fractures, increased frequency or duration of infection, or
abnormal urine color or odor. When the present invention refers to
Multiple Myeloma it refers to (MGUS), smoldering multiple myeloma
(SMM) and active multiple myeloma (MM) as well as other malignant
proliferation of plasma cells that may eventually develop into
active MM.
MGUS, a clinically benign precursor condition of MM is more common
than MM, occurring in 1% of the population over age 50 and 3% of
those over age 70 (Greipp and Lust, 1995). It is important to
distinguish patients with MGUS from those with MM, as MGUS patients
may be safely observed without resort to therapy. However, during
long-term follow-up, of 241 patients with MGUS, 59 patients (24.5%)
went on to develop MM or a related disorder (See Kyle et al.,
1993).
The term gammopathy refers to a primary disturbance in
immunoglobulin synthesis of a patient.
Monoclonal gammopathy refers to any of a group of disorders that
are typically associated with the proliferation of a single clone
of lymphoid or plasma cells (normally visible on serum protein
electrophoresis (SPEP) as a single peak) and characterized by the
presence of monoclonal immunoglobulin in the serum or urine of a
patient.
Smoldering MM (SMM) has been reported to precede the onset of
symptomatic multiple myeloma in the elderly. Smoldering multiple
myeloma is often considered as an advanced phase of MGUS; even at
the time of progression, smoldering multiple myeloma usually lacks
osteolytic lesions or other cardinal features of symptomatic
multiple myeloma.
Clinical symptoms of MM include anemia, hypercalcemia, renal
insufficiency, and lytic bone lesions. Distinctions in the course
and the severity of the disease as it develops from monoclonal
gammopathy of undetermined significance (MGUS) to smoldering
multiple myeloma (SMM) to multiple myeloma (MM) are provided in
Table 3 below. The table also summarizes methods of detection,
diagnosis, and monitoring of these conditions. Such symptoms and
techniques are familiar to those of skill in the art.
TABLE-US-00003 TABLE 3 Comparison of Clinical Features of MM, SMM,
or MGUS Characteristic MM SMM MGUS Marrow plasma Cells >=10%
>=10% <10% Serum M-protein >=3 g/dL >=3 g/dL <3 g/dL
Bence-Jones >=1 g/24 h <1 g/24 h <1 g/24 h protein in
urine Yes Yes Yes Anemia usually present Maybe Absent
Hypercalcemia, renal may be present absent Absent insufficiency
Lytic bone lesions usually present absent Absent MM = multiple
myeloma SMM = smoldering multiple myeloma MGUS = monoclonal
gammopathy of undetermined significance Classifying stages by
severity and clinical features of multiple myeloma Stages of
disease progression Stage I (active MM) Relatively few cancer cells
have spread throughout the body. The number of red blood cells and
the amount of calcium in the blood are normal. No tumors
(plasmacytomas) are found in the bone. The amount of M-protein in
the blood or urine is very low. There may be no symptoms of
disease. Stage II (active MM) A moderate number of cancer cells
have spread throughout the body Stage III (active MM) A relatively
large number of cancer cells have spread throughout the body. There
may be one or more of the following: A decrease in the number of
red blood cells, causing anemia. The amount of calcium in the blood
is very high, because the bones are being damaged. More than three
bone tumors (plasmacytomas) are found. High levels of M-protein are
found in the blood or urine. Clinical features of MM Hypercalcemia
Renal insufficiency Anemia Monoclonal protein: SPEP (serum protein
electrophoresis) SPIEP (serum protein immunoelectrophoresis) Urine
protein immunoelectrophoresis (Bence-Jones protein) Diagnosis of MM
>10% plasma cells in marrow or aggregates on biopsy or a
plasmacytoma Monoclonal protein: Serum M-protein >3 g/dl or
M-protein in urine
Active multiple myeloma (MM) is typically recognized clinically by
the proliferation of malignant plasma cells in the bone marrow of a
patient. These neoplastic plasma cells produce immunoglobulins and
evolve from B-lymphocytes. The immunoglobulins that are produced by
the plasma cells may be detected in the blood serum and/or urine of
a patient by electrophoresis testing.
As indicated in Table 3, the measurement of serum M-protein is an
important tool for assessing MM at different stages.
"M-protein" refers to a monoclonal protein that is typically
visualized as a narrow band on electrophoretic gel, or an abnormal
arc in immunoelectrophoresis. It represents a proliferation of
homogenous immunoglobulin produced by clone cells originating from
a single common cell, e.g., a monoclonal immunoglobulin
characterized by a heavy chain of a single class and subclass, and
light chain of a single type (also referred to as a M-spike and
more broadly as a paraprotein).
"Serum protein electrophoresis" (SPE or SPEP) and "immunofixation
electrophoresis" (IFE) can detect monoclonal immunoglobulin, which
is produced in several plasma cell proliferative disorders
including multiple myeloma (MM). Population-wide, up to 61% of
these findings are not associated with clinical symptoms, allowing
for a diagnosis of monogammopathy of undetermined significance
(MGUS). SPE and IFE do not, however, detect all monoclonal
immunoglobulins, particularly when only light chains are
secreted.
Those "free light chain molecules" (FLCs) include A and K light
chains. Plasma cells produce one of the five heavy chain types
together with either K or A molecules. There is normally
approximately 40% excess free light chain production over heavy
chain synthesis. Plasma cells secrete free light chains (FLC, kappa
or lambda) in addition to intact immunoglobulin molecules, and
serum light chain levels are determined by the relative rates of
synthesis (K>.lamda.) and renal excretion (K>.lamda.). In the
presence of a monoclonal immunoglobulin, K:.lamda. ratios may be
either higher or lower than the normal range, depending on the
class of the involved FLC. The serum half-life of FLCs is 2-6
hours, compared with 5 days for IgA, 6 days for IgM and 21 days for
IgG. Thus, measurement of serum FLC levels allows a far more rapid
evaluation of tumor response to therapy than measurement of intact
immunoglobulin. Likewise, serum FLC measurements allow earlier
detection of relapse.
Non-plasmaproliferative diseases also are associated with CD138
expression.
Pancreatic Carcinoma The majority of cases comprise exocrine type.
The majority of these exocrine cancers represent ductal
adenocarcinoma (further more rare subtypes comprise cystic tumors,
tumors of acinar cells and sarcoma). Endocrine cancer of the
pancreas represents a hormone producing tumor.
Carcinoma in situ refers to the early stage of cancer, when it is
confined to the layer of cells where it began. In breast cancer, in
situ means that the cancer cells remain confined to ducts (ductal
carcinoma in situ) or lobules (lobular carcinoma in situ). They
have not grown into deeper tissues in the breast or spread to other
organs in the body, and are sometimes referred to as non-invasive
or pre-invasive breast cancers. Invasive (infiltrating)
carcinoma.
The exocrine cells and endocrine cells of the pancreas form
completely different types of tumors.
Exocrine Tumors
These are by far the most common type of pancreas cancer and most
pancreatic exocrine tumors are malignant. About 95% of cancers of
the exocrine pancreas are adenocarcinomas (an adenocarcinoma is a
cancer that starts in gland cells). These cancers usually begin in
the ducts of the pancreas, but they sometimes develop from the
cells that make the pancreatic enzymes (acinar cell
carcinomas).
Less common types of ductal cancers of the exocrine pancreas
include adenosquamous carcinomas, squamous cell carcinomas, and
giant cell carcinomas.
Endocrine Tumors
Tumors of the endocrine pancreas are uncommon. As a group, they are
known as pancreatic neuroendocrine tumors (NETs), or sometimes as
islet cell tumors. There are several subtypes of islet cell tumors.
Each is named according to the type of hormone-making cell it
starts in:
The main system used to describe the stages of cancers of the
exocrine pancreas is the American Joint Committee on Cancer (AJCC)
TNM system as provided by the American Cancer Society (ACS). The
TNM system for staging contains 3 key pieces of information:
T describes the size of the primary tumor(s), measured in
centimeters (cm), and whether the cancer has spread within the
pancreas or to nearby organs. Distinctions are made between TX, T0,
T1, T2, T3 and T4, wherein a higher number indicates advancement of
the disease.
N describes the spread to nearby (regional) lymph nodes. N
categories include, NX, NO and N1.
M indicates whether the cancer has metastasized (spread) to other
organs of the body. (The most common sites of pancreatic cancer
spread are the liver, lungs, and the peritoneum--the space around
the digestive organs.) M categories include: MX, M0 and M1.
After the T, N, and M categories have been determined, this
information is combined to assign a stage, a process called stage
grouping.
Stage 0 (Tis, N0, M0): The tumor is confined to the top layers of
pancreatic duct cells and has not invaded deeper tissues. It has
not spread outside of the pancreas. These tumors are sometimes
referred to as pancreatic carcinoma in situ or pancreatic
intraepithelial neoplasia III (PanIn III).
Stage IA (T1, N0, M0): The tumor is confined to the pancreas and is
less than 2 cm in size. It has not spread to nearby lymph nodes or
distant sites.
Stage IB (T2, N0, M0): The tumor is confined to the pancreas and is
larger than 2 cm in size. It has not spread to nearby lymph nodes
or distant sites.
Stage IIA (T3, N0, M0): The tumor is growing outside the pancreas
but not into large blood vessels. It has not spread to nearby lymph
nodes or distant sites.
Stage IIB (T1-3, N1, M0): The tumor is either confined to the
pancreas or growing outside the pancreas but not into nearby large
blood vessels or major nerves. It has spread to nearby lymph nodes
but not distant sites.
Stage III (T4, Any N, M0): The tumor is growing outside the
pancreas into nearby large blood vessels or major nerves. It may or
may not have spread to nearby lymph nodes. It has not spread to
distant sites.
Stage IV (Any T, Any N, M1): The cancer has spread to distant
sites.
Although not formally part of the TNM system, other factors are
also important in determining prognosis (outlook). The grade of the
cancer (how abnormal the cells look under the microscope) is
sometimes listed on a scale from G1 to G4, with G1 cancers looking
the most like normal cells and having the best outlook.
For patients who have surgery, another important factor is the
extent of the resection--whether or not the entire tumor is
removed. This is sometimes listed on a scale from R0 (where all
visible and microscopic tumor was removed) to R2 (where some
visible tumor could not be removed).
From a practical standpoint, how far the cancer has spread often
can't be determined accurately without surgery. That's why doctors
often use a simpler staging system, which divides cancers into
groups based on whether or not it is likely they can be removed
surgically. These groups are called resectable, locally advanced
(unresectable), and metastatic. These terms can be used to describe
both exocrine and endocrine pancreatic cancers.
Resectable: If the cancer is only in the pancreas (or has spread
just beyond it) and the surgeon can remove the entire tumor, it is
called resectable.
Locally advanced (unresectable): If the cancer has not yet spread
to distant organs but it still can't be completely removed with
surgery, it is called locally advanced. Often the reason the cancer
can't be removed is because too much of it is present in nearby
blood vessels.
Metastatic: when the cancer has spread to distant organs, it is
called metastatic. Surgery may still be done, but the goal would be
to relieve symptoms, not to cure the cancer.
Pancreatic neuroendocrine cancers are not staged like cancers of
the exocrine pancreas. Instead the statistics are broken down into
different stages: localized (only in the pancreas), regional
(spread to nearby lymph nodes or tissues), and distant (spread to
distant sites, such as the liver).
Bladder tumors are grouped by the way the cancer cells look under a
microscope.
Transitional cell carcinoma (also called urothelial carcinoma) is
by far the most common type of bladder cancer. Within this group
are also subtypes. They are named depending on the shape of the
cells and whether they tend to spread and invade other organs. (If
they are likely to grow deeper into the bladder wall they are
called invasive, if not likely they are non-invasive.) These tumors
are divided into grades based on how the cells look under the
microscope. If the cells look more like normal cells, the cancer is
called a low-grade cancer. When the cells look very abnormal, the
cancer is high-grade. Lower-grade cancers tend to grow more slowly
and have a better outcome than higher-grade cancers.
Also included in the definition, are squamous cell carcinoma
(uncommon; usually invasive); adenocarcinoma (uncommon; almost all
are invasive); small cell (rare). Other rare bladder cancers are
also included in this definition.
Bladder cancer is also staged:
Stage 0a (Ta, N0, M0):
The cancer is a noninvasive papillary carcinoma. It has grown
toward the hollow center of the bladder but has not grown into the
muscle or connective tissue of the bladder wall. It has not spread
to lymph nodes or distant sites.
Stage 0is (Tis, N0, M0):
The cancer is a flat, noninvasive carcinoma, also known as flat
carcinoma in situ (CIS). The cancer is growing in the lining layer
of the bladder only. It has neither grown inward toward the hollow
part of the bladder nor has it invaded the muscle or connective
tissue of the bladder wall. It has not spread to lymph nodes or
distant sites.
Stage I (T1, N0, M0):
The cancer has grown into the layer of connective tissue under the
lining layer of the bladder without growing into the thick layer of
muscle in the bladder wall. The cancer has not spread to lymph
nodes or to distant sites.
Stage II (T2, N0, M0):
The cancer has grown into the thick muscle layer of the bladder
wall but, it has not passed completely through the muscle to reach
the layer of fatty tissue that surrounds the bladder. The cancer
has not spread to lymph nodes or to distant sites.
Stage III (T3 or T4a, N0, M0):
The cancer has grown completely through the bladder into the layer
of fatty tissue that surrounds the bladder (T3). It may have spread
into the prostate, uterus, or vagina (T4a). It is not growing into
the pelvic or abdominal wall. The cancer has not spread to lymph
nodes or to distant sites.
Stage IV (T4b, N0, M0) or (any T, N 1 to 3, M0) or (any T, any N,
M1):
The cancer has spread through the bladder wall to the pelvic or
abdominal wall (T4b) and/or has spread to lymph nodes (N1-3) and/or
to distant sites such as bones, liver, or lungs (M1).
Types of Gall Bladder Carcinoma
More than 9 out of 10 gallbladder cancers are adenocarcinomas. An
adenocarcinoma is a cancer that starts in the cells with gland-like
properties that line many internal and external surfaces of the
body (including the inside the digestive system).
A type of gallbladder adenocarcinoma that deserves special mention
is called papillary adenocarcinoma or just papillary cancer. These
are gallbladder cancers whose cells are arranged in finger-like
projections when viewed under a microscope. In general, papillary
cancers are not as likely to grow into the liver or nearby lymph
nodes. They tend to have a better prognosis (outlook) than most
other kinds of gallbladder adenocarcinomas. About 6% of all
gallbladder cancers are papillary adenocarcinomas. There are other
types of cancer that can develop in the gallbladder, such as
adenosquamous carcinomas, squamous cell carcinomas, and small cell
carcinomas, but these are uncommon.
Following stages of gall bladder carcinomas are distinguished based
on the TNM system of the AJCC:
Stage 0: Tis, N0, M0: There is a small cancer only in the
epithelial layer of the gallbladder. It has not spread outside of
the gallbladder.
Stage IA: T1(a or b), N0, M0: The tumor grows into the lamina
propria (T1a) or the muscle layer (T1b). It has not spread outside
of the gallbladder.
Stage IB: T2, N0, M0: The tumor grows into the perimuscular fibrous
tissue. It has not spread outside of the gallbladder.
Stage IIA: T3, N0, M0: The tumor extends through the serosa layer
and/or directly grows into the liver and/or one other nearby
structure. It has not spread to lymph nodes or to tissues or organs
far away from the gallbladder.
Stage IIB: T1 to T3, N1, M0: In addition to any growth in the
gallbladder, the tumor has spread to nearby lymph nodes (N1). It
has not spread to tissues or organs far away from the
gallbladder.
Stage III: T4, any N, M0: Tumor invades the main blood vessels
leading into the liver or has reached more than one nearby organ
other than the liver. It may or may not have spread to lymph nodes.
It has not spread to tissues or organs far away from the
gallbladder.
Stage IV: Any T, any N, M1: The tumor has spread to tissues or
organs far away from the gallbladder.
Mammary Carcinoma An adenocarcinoma refers generally to a type of
carcinoma that starts in glandular tissue (tissue that makes and
secretes a substance). In the context of breast cancer, the ducts
and lobules of the breast are glandular tissue, so cancers starting
in these areas are often called adenocarcinomas. There are several
types of breast cancer, although some of them are quite rare. In
some cases a single breast tumor can have a combination of these
types or have a mixture of invasive and in situ cancer.
Ductal carcinoma in situ (DCIS; also known as intraductal
carcinoma) is the most common type of non-invasive breast
cancer.
Invasive (or infiltrating) ductal carcinoma (IDC) is the most
common type of breast cancer. Invasive (or infiltrating) ductal
carcinoma (IDC) starts in a milk passage (duct) of the breast,
breaks through the wall of the duct, and grows into the fatty
tissue of the breast. At this point, it may be able to spread
(metastasize) to other parts of the body through the lymphatic
system and bloodstream. About 8 of 10 invasive breast cancers are
infiltrating ductal carcinomas. IDC patients revealed expression of
CD138 (Loussouarn et al., 2008).
Triple-negative breast cancer describe breast cancers (usually
invasive ductal carcinomas) whose cells lack estrogen receptors and
progesterone receptors, and do not have an excess of the HER2
protein on their surfaces. Triple-negative breast cancers tend to
grow and spread more quickly than most other types of breast
cancer. Because the tumor cells lack these certain receptors,
neither hormone therapy nor drugs that target HER2 are effective
against these cancers (although chemotherapy can still be useful if
needed).
Some other breast cancers that fall under the term "mammary
carcinoma" are Inflammatory breast cancer, medullary carcinoma,
metaplastic carcinoma, mucinous carcinoma, tubular carcinoma,
papillary carcinoma, adenoid cystic carcinoma (adenocystic
carcinoma), phyllodes tumor.
Surgery, radiation or chemotherapy constitutes standard cancer
therapies. Hormone therapy is sometimes employed. Hormone therapy
is a form of systemic therapy. It is most often used as an adjuvant
therapy to help reduce the risk of cancer recurrence after surgery,
although it can be used as neoadjuvant treatment, as well. It is
also used to treat cancer that has come back after treatment or has
spread. Estrogen promotes the growth of about 2 out of 3 of breast
cancers--those containing estrogen receptors (ER-positive cancers)
and/or progesterone receptors (PR-positive cancers). Because of
this, several approaches to blocking the effect of estrogen or
lowering estrogen levels are used to treat ER-positive and
PR-positive breast cancers. However, hormone therapy is ineffective
for patients lacking ERs or PRs.
Mammary carcinoma also follows such a staging system:
Stage 0: Atypical cells have not spread outside of the ducts or
lobules, the milk producing organs, into the surrounding breast
tissue. Referred to as carcinoma in situ, it is classified in two
types: "Ductal Carcinoma In Situ" (DCIS), which is very early
cancer that is highly treatable and survivable and "Lobular
Carcinoma In Situ" (LCIS), which is not a cancer but an indicator
that identifies a woman as having an increased risk of developing
breast cancer.
Stage I: The cancer is no larger than two centimeters
(approximately an inch) and has not spread to surrounding lymph
nodes or outside the breast.
Stage II: This stage is divided into two categories according to
the size of the tumor and whether or not it has spread to the lymph
nodes:
Stage II A Breast Cancer--the tumor is less than two centimeters
and has spread up to three auxiliary underarm lymph nodes. Or, the
tumor has grown bigger than two centimeters, but no larger than
five centimeters and has not spread to surrounding lymph nodes.
Stage II B Breast Cancer--the tumor has grown to between two and
five centimeters and has spread to up to three auxiliary underarm
lymph nodes. Or, the tumor is larger than five centimeters, but has
not spread to the surrounding lymph nodes.
Stage III: This stage is also divided into two categories:
Stage III: A Breast Cancer--the tumor is larger than two
centimeters but smaller than five centimeters and has spread to up
to nine auxiliary underarm lymph nodes.
Stage III B Breast Cancer--the cancer has spread to tissues near
the breast including the skin, chest wall, ribs, muscles, or lymph
nodes in the chest wall or above the collarbone.
Stage IV: Here, the cancer has spread to other organs or tissues,
such as the liver, lungs, brain, skeletal system, or lymph nodes
near the collarbone.
Lung Cancer
There are 4 types of neuroendocrine lung tumors, namely, large cell
neuroendocrine carcinoma, atypical carcinoid tumor, typical
carcinoid tumor and small cell lung cancer. Carcinoid tumors are
tumors that start from cells of the diffuse neuroendocrine system.
Typical and atypical carcinoid tumors look different under the
microscope. Typical carcinoids grow slowly and only rarely spread
beyond the lungs and about 9 out of 10 lung carcinoids are typical
carcinoids.
For treatment purposes two main types of lung cancer, which are
very differently treated, are distinguished, namely, small cell
lung cancer (SCLC) and non-small cell lung cancer (NSCLC). If the
cancer has features of both types, it is called mixed small
cell/large cell cancer.
About 10% to 15% of all lung cancers are the small cell type. Other
names for SCLC are oat cell carcinoma and small cell
undifferentiated carcinoma.
This cancer often starts in the bronchi near the center of the
chest. Although the cancer cells are small, they can divide
quickly, form large tumors, and spread to lymph nodes and other
organs throughout the body. Surgery is rarely an option and never
the only treatment given. Treatment includes cytotoxic agents, such
as drugs to kill the widespread disease.
There are 3 sub-types of NSCLC, namely squamous cell carcinoma;
adenocarcinoma; large-cell (undifferentiated) carcinoma.
Staging of Non-Small Cell Lung Cancer
The system used to stage non-small cell lung cancer is the AJCC
(American Joint Committee on Cancer) system. Stages are described
using Roman numerals from 0 to IV (0 to 4). Some stages are further
divided into A and B. As a rule, the lower the number, the less the
cancer has spread. A higher number, such as stage IV (4), means a
more advanced cancer.
A respective staging system, including Stages I to IV, was also
developed for squamous cell carcinoma (head and neck cancer). Stage
I cancers are small, localized and usually curable, stage II and
III cancers typically are locally advanced and/or have spread to
local lymph nodes and Stage IV cancers usually are metastatic (have
spread to distant parts of the body) and generally are considered
inoperable.
Treatment in the context of the present invention includes
preventing or slowing the progression, stabilizing the disease
state, remitting the disease or ameliorating one or more symptoms
of a disorder associated with cells expressing CD138. Treatment
thus includes preventing or slowing down the increase of severity
or the remission of the disorder. In the case of MM generally only
patients with stage II or III active MM receive primary therapy
(stage I patients or patients with SMM are initially only observed
in 3 to 6 month intervals), a treatment according to the present
invention does not only include the treatment of, e.g., any active
stage of MM, but also includes the treatment of forms of disease
states that precede the traditionally treated disease state.
Treatment in particular also includes preventing the progression
from one disease state to the next: in the case of MM, this would,
e.g., be the progression from MGUS to SMM or from SMM to active MM
stage I or another stage of MM. In case of cancers of the exocrine
pancreas, e.g., a progression from Stage I to Stage II, including
any worsening as reflected by the categories established by the
AJCC within the stages, e.g. from IA to IB. However, the term also
includes maintaining the status quo, such as to maintain stable
disease and, as discussed below, eliciting certain responses in the
patient treated. A patient is also successfully "treated" if the
patient shows observable and/or measurable reduction in or absence
of, inter alia, one or more of the following: reduction in the
number of cancer cells or absence of the cancer cells; reduction in
the tumor size; inhibition (i.e., slow to some extent and
preferably stop) of cancer cell infiltration into peripheral organs
including the spread of cancer into soft tissue and bone;
inhibition (i.e., slow to some extent and preferably stop) of tumor
metastasis; inhibition, to some extent, of tumor growth; and/or
relief to some extent, one or more of the symptoms associated with
the specific cancer; reduced morbidity and mortality, and
improvement in quality of life issues. In general, an effect of a
certain treatment on the disease status of a patient can be
monitored, in the case of MM, by measuring the M-protein levels in
the patient's serum and/or urine and/or the FLC levels in the
patient's serum and/or urine. In the case of other disorders
associated with cells expressing CD138, other parameters are
measured to assess the effect of a treatment according to the
present invention. CRP(C-reactive protein) is an unspecific
inflammation parameter for clinical cancer monitoring. To name just
a few, for pancreatic cancer, relevant parameters that may be
measured are CA 19-9 (carbohydrate antigen 19.9, a tumor marker
often elevated in pancreatic cancer), bilirubin, or CRP. In
addition imaging such as sonography, CT, MRT are used. In head and
neck cancer, biomarkers which depend on the tumor type are used
(e.g., NSE (neuron-specific enolase) for Merkel cell or CEA
(carcinoembryonic antigen); in breast carcinoma, CA 15-3Her.sub.2
expression and Cadherin expression may be used as markers, while
the treatment is monitored by serum markers such as NSE.
The bladder tumor antigen (BTA) and the NMP22 tests can be used
along with cystoscopy (using a thin, lighted tube to look in the
bladder) in diagnosing the condition in symptomatic subjects. These
tests are also being used to follow some patients after treatment,
though cystoscopy and urine cytology (using a microscope to look
for cancer cells in the urine) are still recommended as the
standard tests for diagnosis and follow-up. BTA and NMP22 tests are
often used between cystoscopies. Normal values may allow cystoscopy
to be done less often. However, these test tests cannot replace
urine cytology and cystoscopy.
For advanced bladder cancer, some of the markers used for other
cancers such as CEA, CA 125, CA 19-9, and TPA (tissue polypeptide
antigen) may be elevated and can be used to follow patients during
and after treatment. For lung cancer, no established marker exists,
but CEA pr NSE might be elevated.
Tumor cells such as myeloma cells or mammary carcinoma cells are
known to shed CD138. The loss of surface CD138 is correlated with
poor prognosis in myeloma. High levels of soluble CD138 have been
also detected in other oncologic indications such as head and neck
or lung cancer (Anttonen et al. 1999). The loss of surface
Syndecan-1 is correlated with EMT (epithelial mesenchymal
transition) this process describes the transformation of a
malignant cell into a less or poorly differentiated cell associated
with invasiveness and metastatic stage. This is e.g. reported for
metastatic breast cancer (Loussouarn et al., 2008).
An effective amount of an agent, in particular, an immunoconjugate
or a pharmaceutical composition comprising an immunoconjugate
according to the present invention refers to an amount required to
"treat" a disease or disorder in a subject, in particular a human
subject (patient). In the case of cancer such as MM, the effective
amount of the agent may reduce the number of cancer cells; reduce
the tumor size; inhibit (i.e., slow to some extent and preferably
stop) cancer cell infiltration into peripheral organs; inhibit
(i.e., slow to some extent and preferably stop) tumor metastasis;
inhibit, to some extent, tumor growth; and/or relieve to some
extent, one or more of the symptoms associated with the cancer. See
the definition herein of "treatment".
"A pharmacokinetic equivalent" of, e.g., 200 mg/m.sup.2 refers to
the amount of immunoconjugate that results in equal
pharmacokinetics observed at dosages of 200 mg/m.sup.2 when the
immunoconjugate is administered in combination, including
co-administered with an agent for treating actual including
potential adverse side effects primarily on non-target cells that
also express CD138. Those equivalents might be somewhat less than
200 or somewhat more than 200, depending on the other agent.
Included are, e.g., effective amounts of less than 160, less than
170, less than 180, less than 190 and less than 210, less than 220,
less than 230 and less than 240 mg/m.sup.2. For example, the person
skilled in the art would expect that co-administration with
corticosteroids or with antibiotics would allow slightly higher
doses of the immunoconjugate even in cases of side effects on skin,
which, can, however, be readily ascertained by the person skilled
in the art.
To evaluate the success of the administration of a drug, here an
immunoconjugate (i.e., its ability to produce a functional
response, i.e., its efficacy), different "responses" to an
administration are distinguished.
Responses are often evaluated by measuring efficacy blood
parameters. Typical efficacy blood parameters are M-protein level,
FLC level or other markers that correlate to the disease in
question to the efficacy of the immunoconjugate (disease specific
marker), in particular the cancer in question. The efficacy
indicates the capacity for beneficial change of a given
treatment.
In the context of MM and other plasmaproliferative diseases,
responses are distinguished as follows:
the term complete response (CR) refers to the negative
immunofixation of serum and urine and disappearance of any soft
tissue plasmacytomas and <5% plasma cells in bone marrow;
the term stringent complete response (sCR) refers to CR as defined
above, plus normal FLC ratio and absence of clonal cells in bone
marrow by immunohistochemistry or immunofluorescence;
the term very good partial response (VGPR) refers to serum and
urine M-component detectable by immunofixation, but not on
electrophoresis or .ltoreq.90% or greater reduction in serum
M-component plus urine M-component <100 mg per 24 h;
the term partial response (PR) refers to .ltoreq.50% reduction of
serum M protein and reduction in 24-h urinary M protein by
.gtoreq.90% or to <200 mg per 24 h, if the serum and urine M
protein are immeasurable, a .gtoreq.50% decrease in the difference
between involved and uninvolved FLC levels is required in place of
the M protein criteria, if serum and urine M protein are
immeasurable, and serum free light assay is also immeasurable,
.gtoreq.50% reduction in bone marrow plasma cells is required in
place of M protein, provided baseline percentage was .gtoreq.30%,
in addition to the above criteria, if present at baseline,
.gtoreq.50% reduction in the size of soft tissue plasmacytomas is
also required (Durie et al., 2006).
The term minor response (MR) in relation to patients with
relapsed/refractory myeloma refers in the context of the present
invention to .gtoreq.25% but <49% reduction of serum M protein
and reduction in 24 h urine M protein by 50-89%, which still
exceeds 200 mg per 24 h, in addition to the above criteria, if
present at baseline, 25-49% reduction in the size of soft tissue
plasmacytomas is also required, no increase in size or number of
lytic bone lesions (development of compression fracture does not
exclude response).
However, a response, though not formally classified, also includes
an at least 30%, preferably at least 40% or 50% reduction in serum
FLC levels. This is in particular of significance in cases where
M-protein cannot be measured.
The term stable disease (SD) refers, in the context of the
plasmaproliferative diseases of the present invention, to the not
meeting of the criteria for CR, VGPR, PR or progressive disease,
while the term progressive disease (PD) refers to the increase of
25% from lowest response value in any one or more of the following:
Serum M-component (absolute increase must be .gtoreq.0.5 g/100 ml)
and/or Urine M-component (absolute increase must be .gtoreq.200 mg
per 24 h) and/or Only in patients without measurable serum and
urine M-protein levels: the difference between involved and
uninvolved FLC levels (absolute increase must be >100 mg/l) Bone
marrow plasma cell percentage (absolute % must be .gtoreq.10%)
Definite development of new bone lesions or soft tissue
plasmacytomas or definite increase in the size of existing bone
lesions or soft tissue plasmacytomas Development of hypercalcemia
(corrected serum calcium >11.5 mg/100 ml) that can be attributed
solely to the plasma cell proliferative disorder.
The term relapsed myeloma refers herein to a form of active MM in a
subject, wherein said subject underwent at least one prior
treatment regime, and which does not meet the criteria for
relapsed/refractory myeloma.
The term refractory myeloma generally refers to a state of the
disease when the number of plasma cells continues to increase even
though treatment is give, that is the disease has, at the time of
assessment, been proven irrespective to the treatment regime
administered.
The term relapsed/refractory myeloma refers herein to the relapse
of disease while on salvage therapy, or progression within 60 days
of most recent therapy.
The term refractory phenotype includes any type of refractory
myeloma, that is, refractory and relapsed/refractory myeloma.
The term relapsed or refractory myeloma covers relapsed, refractory
and relapsed/refractory myeloma.
A tumor or a CD138 target cell is said to be refractory to, e.g., a
therapy/treatment if the CD 138 target cell continues dividing
and/or the tumor continues growing at the same rate during such a
therapy/therapy as without such therapy/treatment.
Tumor growth delay refers to a tumor growth that is delayed
relative to regular tumor growth without treatment.
Tumor stasis refers to a state at which there is no further growth
in tumor size.
Remission refers to a decrease in tumor size (partial remission),
including the complete eradication of the tumor and absence of
regrowth (complete remission).
Hormone therapy includes a therapy with a hormone. Cancer hormone
therapy is employed to fight target cells. A hormone therapy is
used, e.g., in the context of mammary carcinoma or prostate cancer
and include the administration of estrogen and progesterone or
derivatives thereof.
Chemotherapy is the treatment of cancerous cells with an
antineoplastic drug such as taxane or with a combination of such
drugs in a standardized treatment regime.
Maintenance therapy is a therapy that follows a prior treatment,
and aims at maintaining the status obtained when completing said
primary treatment. For example, if the prior treatment resulted in
a partial response, the maintenance therapy is designed to maintain
partial response.
In the clinical study discussed in more detail below, the subjects
had been treated with at least one immunomodulator and a proteosome
inhibitor therapy, which have failed, prior to entering the study.
Disease was considered treatment refractory if the subject
experienced progressive disease (PD) on his or her previous
regimen.
The term "progression to", e.g., "active MM" in relation to
patients with SMM refers in the context of the present invention to
evidence of progression based on the IMWG (International Myeloma
Working Group) criteria for progressive disease in MM and any one
or more of the following felt related to the underlying clonal
plasma cell proliferative disorder, development of new soft tissue
plasmacytomas or bone lesions, hypercalcemia (>11 mg/100 ml),
decrease in hemoglobin of .gtoreq.2 g/100 ml, and serum creatinine
level .gtoreq.2 mg/100 ml. (Kyle & Rajkumar, 2009).
Progression free survival is the duration from start of a treatment
to disease progression or death (regardless of cause of death),
whichever comes first. When a reference is made to "progression
free survival" without a reference to time period, lack of
progression of more than 3 months is implied.
The pathogenesis of multiple myeloma involves binding of myeloma
cells, via cell-surface adhesion molecules, to bone marrow stroma
cells (BMSCs) as well as the extracellular matrix (ECM). This
binding triggers, and thus can be made ultimately responsible, for
multiple myeloma cell growth, drug resistance, and migration of MM
cells in the bone marrow milieu (Munshi et al. 2008). In
particular, the adhesion of multiple myeloma cells to ECM via
syndecan-1 (CD138) to type I collagen induces the expression of
matrix metalloproteinase 1, thus promoting bone resorption and
tumor invasion (Hideshima et al. 2007). Interactions between
multiple myeloma cells and the bone marrow microenvironment results
in activation of a pleiotropic proliferative and anti-apoptotic
cascade.
For multiple myeloma patients, but also for patients suffering from
other diseases that are associated with bone pains, a number of
supportive treatments exist to treat this and other symptoms.
Appropriate medications include bisphosphonates (e.g. pamidronate,
zoledronic acid) which can slow the bone damage. It has been
demonstrated that these agents are able to reduce osteolytic bone
lesions and prevent fractures (Ludwig et al., 2007). They are
mostly given through a vein to decrease the risk of bone
complications like fractures and to lower abnormally high blood
calcium levels (Hypercalcemia). Data suggests that bisphosphonates
reduce bone pain associated with MM. Patients may also have surgery
if their bones are weak or break.
In one embodiment, the immunoconjugates reduce; in particular
reduce to an acceptable level, bone pains and/or bone
complications, such as osteonecrosis. A reduction to an acceptable
level involves in particular the ability to discontinue the
administration of a medication that alleviates these pains or is
aimed at reducing said bone complications. Bisphosphonates, such as
pamidronate, zoledronic acid and clodronate, are commonly
administered to alleviate bone complications, such as osteonecrosis
in MM patients and thereby to alleviate bone pains associated with
said complications. Common bisphosphonates include, for oral
administration, FOSOMAX, BONIVA, ACTONEL, DIDRONEL and SKELID, for
intravenous administration, BONEFOS, AREDIA and ZOMETA.
Following the homing of multiple myeloma cells to the bone marrow
stromal compartment, adhesion between multiple myeloma cells and
BMSCs upregulates many cytokines like interleukin-6 (IL-6) and
insulin like growth factor 1 (IGF-1) which have angiogenic and
tumor growth promoting activities (Hideshima et al. 2007). The
signalling cascades initiated by these cytokines eventually result
in MM cell resistance to conventional therapeutics (Anderson et al.
2000; Hideshima et al. 2006).
In the normal human hematopoietic compartment, CD138 expression is
restricted to plasma cells (Wijdenes, 1996; Chilosi, 1999) and
CD138 is not expressed on peripheral blood lymphocytes, monocytes,
granulocytes, and red blood cells. In particular, CD34.sup.+ stem
and progenitor cells do not express CD138, and anti-CD138 mAbs do
not affect the number of colony forming units in hematopoietic stem
cell cultures (Wijdenes, 1996). In non-hematopoietic compartments,
CD138 is mainly expressed on simple and stratified epithelia within
the lung, liver, skin, kidney and gut. Only a weak staining was
seen on endothelial cells (Bernfield, 1992; Vooijs, 1996). It has
been reported that CD138 exists in polymorphic forms in human
lymphoma cells (Gattei, 1999). CD138 epithelial tissue of the
gastrointestinal tract, skin, and eye are the non-target tissues
that are most prone to be targeted by immunoconjugates of the
present invention resulting in toxicities.
Monoclonal antibodies B-B4, BC/B-B4, B-B2, DL-101, 1 D4, MI15,
1.BB.210, 2Q1484, 5F7, 104-9, 281-2 in particular B-B4 have been
reported to be specific to CD138. Of those B-B4, 1 D4 and MI15
recognized both the intact molecule and the core protein of CD138
and were shown to recognize either the same or closely related
epitopes (Gattei, 1999). Previous studies reported that B-B4 did
not recognize soluble CD138, but only CD138 in membrane bound form
(Wijdenes, 2002).
The initial anti-CD138 antibody was developed by Diaclone SAS
(Besancon, France) as the murine parental Mab B-B4 generated by
immunization with the human multiple myeloma cell line U266, using
standard hybridoma technology (Clement, 1995; Wijdenes, 1996). B-B4
binds to a linear epitope between residues 90-93 of the core
protein on human syndecan-1 (CD138) (Wijdenes, 1996; Dore, 1998).
Consistent with the expression pattern of CD138, B-B4 was shown to
strongly react with plasma cell line RPMI8226, but not to react
with endothelial cells. Also consistent with the expression pattern
of CD138, B-B4 also reacted with epithelial cells lines A431
(keratinocyte derived) and HepG2 (hepatocyte derived). An
immunotoxin B-B4-saporin was also highly toxic towards the plasma
cell line RPMI8226, in fact considerably more toxic than free
saporin. However, from the two epithelial cell lines tested,
B-B4-saporin showed only toxicity towards cell line A431, although
in a clonogenic assay B-B4-saporin showed no inhibitory effect on
the outgrowth of A431 cells (Vooijs, 1996).
Other researchers reported lack of specificity of MM-associated
antigens against tumors (Couturier, 1999).
B-B4 covalently linked to the maytansinoid DM1 showed selective
cytotoxicity on multiple myeloma cell lines and cells, as well as
anticancer activity in human multiple myeloma xenograft models in
SCID mice (Tassone, 2004).
The present invention uses the term tumor cell to include cancer
cells as well as pre-cancerous cells which may or may not form part
of a solid tumor. Preferred tumor cells to be treated are cells of
hematopoietic malignancies.
A solid tumor according to the present invention is an abnormal
mass of tissue that usually does not contain cysts or liquid areas.
A solid tumor according to the present invention comprises target
tumor cells expressing CD138 and thus is a malignant solid tumor.
Different types of solid tumors are named for the type of cells
that form them. Examples of solid tumors are sarcomas, carcinomas,
and lymphomas. Hematopoietic malignancies generally do not form
solid tumors. Mammary carcinoma and prostate carcinoma are two
examples of malignant solid tumors.
A targeting agent according to the present invention is able to
associate with a molecule expressed by a target cell and includes
peptides and non-peptides. In particular, targeting agents
according to the present invention include targeting antibodies and
non-immunoglobulin targeting molecules, which may be based on
non-immunoglobulin proteins, including, but not limited to,
AFFILIN.RTM. molecules, ANTICALINS.RTM. and AFFIBODIES.RTM..
Non-immunoglobulin targeting molecules also include non-peptidic
targeting molecules such as targeting DNA and RNA oligonucleotides
(aptamers), but also physiological ligands, in particular ligands
of the antigen in question, such as CD138.
A targeting antibody according to the present invention is or is
based on a natural antibody or is produced synthetically or by
genetic engineering and binds to an antigen on a cell or cells
(target cell(s)) of interest. A targeting antibody according to the
present invention includes a monoclonal antibody, a polyclonal
antibody, a multispecific antibody (for example, a bispecific
antibody), or an antibody fragment. The targeting antibody may be
engineered to, for example, improve its affinity to the target
cells (Ross, 2003) or diminish its immunogenicity. The targeting
antibody may be attached to a liposomal formulation including
effector molecules (Carter, 2001). An antibody fragment comprises a
portion of an intact antibody, preferably the antigen binding or
variable region of the intact antibody. Examples of antibody
fragments according to the present invention include Fab, Fab',
F(ab').sub.2, and Fv fragments, but also diabodies; domain
antibodies (dAb) (Ward, 1989; U.S. Pat. No. 6,005,079); linear
antibodies; single-chain antibody molecules; and multispecific
antibodies formed from antibody fragments. In a single chain
variable fragment antibody (scFv) the heavy and light chains (VH
and VL) can be linked by a short amino acid linker having, for
example, the sequence (glycine.sub.4serine).sub.n, which has
sufficient flexibility to allow the two domains to assemble a
functional antigen binding pocket. Addition of various signal
sequences may allow for more precise targeting of the targeting
antibody. Addition of the light chain constant region (CL) may
allow dimerization via disulphide bonds, giving increased stability
and avidity. Variable regions for constructing the scFv can, if a
mAb against a target of interest is available, be obtained by
RT-PCR which clones out the variable regions from mRNA extracted
from the parent hybridoma. Alternatively, the scFv can be generated
de novo by phage display technology (Smith, 2001). As used herein,
the term "functional fragment", when used in reference to a
targeting antibody, is intended to refer to a portion of the
targeting antibody which is capable of specifically binding an
antigen that is specifically bound by the antibody reference is
made to. A bispecific antibody according to the present invention
may, for example, have at least one arm that is reactive against a
target tissue and one arm that is reactive against a linker moiety
(United States Patent Publication 20020006379). A bispecific
antibody according to the present invention may also bind to more
than one antigen on a target cell (Carter, 2001). An antibody
according to the present invention may be modified by, for example,
introducing cystein residues to introduce thiol groups (Olafsen,
2004).
In accordance with the present invention, the targeting antibody
may be derived from any source and may be, but is not limited to, a
camel antibody, a murine antibody, a chimeric human/mouse antibody
or a chimeric human/monkey antibody, in particular, a chimeric
human/mouse antibody such as nBT062.
Humanized antibodies are antibodies that contain sequences derived
from a human-antibody and from a non-human antibody and are also
within the scope of the present invention. Suitable methods for
humanizing antibodies include CDR-grafting (complementarity
determining region grafting) (EP 0 239 400; WO 91/09967; U.S. Pat.
Nos. 5,530,101; and 5,585,089), veneering or resurfacing (EP 0 592
106; EP 0 519 596; Padlan, 1991; Studnicka et al., 1994; Roguska et
al., 1994), chain shuffling (U.S. Pat. No. 5,565,332) and
Delmmunosation.TM. (Biovation, LTD). In CDR-grafting, the mouse
complementarity-determining regions (CDRs) from, for example, mAb
B-B4 are grafted into human variable frameworks, which are then
joined to human constant regions, to create a human B-B4 antibody
(hB-B4). Several antibodies humanized by CDR-grafting are now in
clinical use, including MYLOTARG (Sievers et al., 2001) and
HECEPTIN (Pegram et al, 1998).
The resurfacing technology uses a combination of molecular
modeling, statistical analysis and mutagenesis to alter the non-CDR
surfaces of antibody variable regions to resemble the surfaces of
known antibodies of the target host. Strategies and methods for the
resurfacing of antibodies, and other methods for reducing
immunogenicity of antibodies within a different host, are
disclosed, for example, in U.S. Pat. No. 5,639,641. Human
antibodies can be made by a variety of methods known in the art
including phage display methods. See also U.S. Pat. Nos. 4,444,887,
4,716,111, 5,545,806, and 5,814,318; and international patent
application publications WO 98/46645, WO 98/50433, WO 98/24893, WO
98/16654, WO 96/34096, WO 96/33735, and WO 91/10741.
Targeting antibodies that have undergone any non-natural
modification such as chimeric human/mouse antibodies or a chimeric
human/monkey antibodies, humanized antibodies or antibodies that
were engineered to, for example, improve their affinity to the
target cells or diminish their immunogenicity but also antibody
fragments, in particular functional fragments of such targeting
antibodies that have undergone any non-natural modification,
diabodies; domain antibodies; linear antibodies; single-chain
antibody molecules; and multispecific antibodies are referred to
herein as engineered targeting antibodies.
Chimerized antibodies, maintain the antibody binding region (ABR or
Fab region) of the non-human antibody, e.g., the murine antibody
they are based on, while any constant regions may be provided for
by, e.g., a human antibody. Generally, chimerization and/or the
exchange of constant regions of an antibody will not affect the
affinity of an antibody because the regions of the antibody which
contribute to antigen binding are not affected by this exchange. In
a preferred embodiment of the present invention, the engineered, in
particular chimerized, antibody of the present invention, may have
a higher binding affinity (as expressed by K.sub.D values) than the
respective non-human antibody it is based on. In particular, the
nBT062 antibody and antibodies based thereon may have higher
antibody affinity than the murine B-B4.
In another preferred embodiment of the present invention,
immunoconjugates comprising those engineered/chimerized antibodies
also display this higher antibody affinity. These immunoconjugates
may also display in certain embodiments other advantageous
properties, such as a higher reduction of tumor load than their
B-B4 containing counterparts. In a preferred embodiment, the
engineered, in particular chimerized targeting antibodies display
binding affinities that are characterized by dissociation constants
K.sub.D (nM) of less than 1.6, less than 1.5 or about or less than
1.4, while their murine counterparts are characterized by
dissociation constants K.sub.D (nM) of about or more than 1.6.
Immunoconjugates comprising targeting agents such as targeting
antibodies may be characterized by dissociation constants of
K.sub.D (nM) of less than 2.6, less than 2.5, less than 2.4, less
than 2.3, less than 2.2, less than 2.1, less than 2.0, less than or
about 1.9 are preferred, while immunoconjugates comprising the
murine counterpart antibodies may be characterized by dissociation
constants K.sub.D (nM) of about or more than 2.6 (compare Table 12
Materials and Methods).
The basic antibody molecule is a bifunctional structure wherein the
variable regions bind antigen while the remaining constant regions
may elicit antigen independent responses. The major classes of
antibodies, IgA, IgD, IgE, IgG and IgM, are determined by the
constant regions. These classes may be further divided into
subclasses (isotypes). For example, the IgG class has four
isotypes, namely, IgG1, IgG2, IgG3, and IgG4 which are determined
by the constant regions. Of the various human antibody classes,
only human IgG1, IgG2, IgG3 and IgM are known to effectively
activate the complement system. While the constant regions do not
form the antigen binding sites, the arrangement of the constant
regions and hinge region may confer segmental flexibility on the
molecule which allows it to bind with the antigen.
Different IgG isotypes can bind to Fc receptors on cells such as
monocytes, B cells and NK cells, thereby activating the cells to
release cytokines. Different isotypes may also activate complement,
resulting in local or systemic inflammation. In particular, the
different IgG isotypes may bind Fc.gamma.R to different degrees.
Fc.gamma.Rs are a group of surface glycoproteins belonging to the
Ig superfamily and expressed mostly on leucocytes. The Fc.gamma.R
glycoproteins are divided into three classes designated Fc.gamma.RI
(CD64), Fc.gamma.RII (CD32) and Fc.gamma.RIII (CD16). While IgG1,
IgG2 and IgG3 bind strongly to a variety of these classes of
Fc.gamma.R glycoproteins, IgG4 displays much weaker binding. In
particular, IgG4 is an intermediate binder of Fc.gamma.RI, which
results in relatively low or even no ADCC (antibody dependent
cellular cytotoxicity), and does not bind to Fc.gamma.RIIIA or
Fc.gamma.RIIA. IgG4 is also a weak binder of Fc.gamma.RIIB, which
is an inhibitory receptor. Furthermore, IgG4 mediates only weak or
no complement fixation and weak or no complement dependent
cytotoxicity (CDC). In the context of the present invention, IgG4
may be specifically employed to prevent Fc-mediated targeting of
hepatic FcR as it displays no interaction with FcR.gamma.II on
LSECs (liver sinusoidal endothelial cells), no or weak interaction
with FcR.gamma.I-III on Kupffer cells (macrophages) and no
interaction with FcR.gamma.III on hepatic NK cells. Certain
mutations that further reduce any CDC are also part of the present
invention. For example IgG4 residues at positions 327, 330 and 331
were shown to reduce ADCC (antibody dependent cellular
cytotoxicity) and CDC (Amour, 1999; Shields, 2001). One of more
mutations that stabilize the antibody is also part of the present
invention (also referred to herein as "stabilizing mutations").
Those mutations include in particular, leucine-to-glutamic acid
mutations in the CH2 region of IgG4 and serine-to-proline exchanges
in the IgG4 hinge core. These mutations decrease, in certain
embodiments of the invention, the amount of half-molecules to less
than 10%, less than 5% and preferably less than 2% or 1%. Moreover,
the in vivo half life of so stabilized antibodies might be
increased several days, including 1, 2, 3, 4 or more than 5 days
(Schuurman, 1999).
When the present invention refers to an immunoconjugate comprising
an engineered targeting antibody conferring IgG4 isotype
properties, this means that the engineered targeting antibody shows
significantly reduced affinity to Fc receptor expressing cells as
compared to the affinity of antibodies of IgG1 isotype. These
properties are preferably conferred by a further antibody region,
which is distinct from the ABR, wherein said further antibody
region is in whole or part of a human antibody. The result is a
significantly reduced (more than 90% relative to its IgG1 isotype
counterpart) or the total lack of a potential to induce CDC or ADCC
as compared to the potential to induce CDC or ADCC usually observed
with IgG1 isotype antibodies. This property can be measured in cell
based assays by using the engineered targeting antibody in its
unconjugated form. CDC and ADCC can be measured via different
methods such as the one disclosed in Cancer Immunol. Immunother.,
36, 373 (1993) or the GUAVA Cell Toxicity Assay. The overall
benefit of immunoconjugates comprising at least part of an
engineered targeting antibody conferring IgG4 isotype properties is
an improvement of binding specificity and a reduced toxicity. Also
the resulting reduced affinity to Fc receptors improves
antigen-specific targeting of tumor cells leading to reduced
toxicity against CD138 negative cells.
Targeting agents, including targeting antibodies disclosed herein
may also be described or specified in terms of their binding
affinity to an antigen, in particular to CD138. Preferred binding
affinities of targeting agents such as targeting antibodies are
characterized by dissociation constants K.sub.D (nM) of less than
1.6, less than 1.5 or about or less than 1.4. For immunoconjugates
comprising said targeting agents such as targeting antibodies
dissociation constants K.sub.D (nM) of less than 1.6, less than 1.5
or less than 2.5, less than 2.4, less than 2.3, less than 2.2, less
than 2.1, less than 2.0, less than or about 1.9 are preferred.
An antigen binding region (ABR) according to the present invention
will vary based on the type of targeting antibody or engineered
targeting antibody employed. In a naturally occurring antibody and
in most chimeric and humanized antibodies, the antigen binding
region is made up of a light chain and the first two domains of a
heavy chain. However, in a heavy chain antibody devoid of light
chains, the antigen binding region will be made up of, e.g., the
first two domains of the heavy chain only, while in single chain
antibodies (ScFv), which combine in a single polypeptide chain the
light and heavy chain variable domains of an antibody molecule, the
ABR is provided by only one polypeptide molecule. FAB fragments are
usually obtained by papain digestion and have one light chain and
part of a heavy chain and thus comprise an ABR with only one
antigen combining site. On the other hand, diabodies are small
antibody fragments with two antigen-binding regions. In the context
of the present invention, however, an antigen binding region of a
targeting antibody or on engineered targeting antibody is any
region that primarily determines the binding specificity of the
targeting antibody or the engineered targeting antibody.
If an ABR or another targeting antibody region is said to be "of a
certain antibody", e.g., a human or non-human antibody, this means
in the context of the present invention that the ABR is either
identical to a corresponding naturally occurring ABR or is based
thereon. An ABR is based on a naturally occurring ABR if it has the
binding specificity of the naturally occurring ABR. However, such
an ABR may comprise, e.g., point mutations, additions, deletions or
posttranslational modification such as glycosylation. Such an ABR
may in particular have more than 70%, more than 80%, more than 90%,
preferably more than 95%, more than 98% or more than 99% sequence
identity with the sequence of the naturally occurring ABR.
nBT062 (see also FIG. 1) is a murine human chimeric IgG4 mAb,
namely a chimerized version of B-B4. This chimerized version of
B-B4 was created to reduce the HAMA (Human Anti-Mouse Antibody)
response, while maintaining the functionality of the antibody
binding region of the B-B4 for CD138. Surprisingly, the results
obtained using an immunoconjugate comprising this engineered
targeting antibody were much more homogenous (the variance in the
results was reduced). The protocol for producing nBT062 is
specified below. Chinese hamster ovary cells expressing nBT062 have
been deposited with the DSMZ-Deutsche Sammlung von Mikroorganismen
and Zellkulturen GmbH, Mascheroder Weg 1, D-38124 Braunschweig on
Dec. 11, 2007. The identification number is DSM ACC2875. A CD138
specific chimeric antibody based on B-B4 is generically referred to
herein as c-B-B4.
The amino acid sequence for both the heavy and the light chains has
been predicted from the translation of the nucleotide sequence for
nBT062. The amino acid sequences predicted for the heavy chain and
light chain are presented in Table 4. Predicted variable regions
are bolded, predicted CDRs are underlined.
TABLE-US-00004 TABLE 4 Predicted Amino Acid Sequence for nBT062
nBT062 heavy chain predicted sequence (SEQ ID NO: 1): 1 QVQLQQSGSE
LMMPGASVKI SCKATGYTFS NYWIEWVKQR PGHGLEWIGE 51 ILPGTGRTIY
NEKFKGKATF TADISSNTVQ MQLSSLTSED SAVYYCARRD 101 YYGNFYYAMD
YWGQGTSVTV SSASTKGPSV FPLAPCSRST SESTAALGCL 151 VKDYFPEPVT
VSWNSGALTS GVHTFPAVLQ SSGLYSLSSV VTVPSSSLGT 201 KTYTCNVDHK
PSNTKVDKRV ESKYGPPCPS CPAPEFLGGP SVFLFPPKPK 251 DTLMISRTPE
VTCVVVDVSQ EDPEVQFNWY VDGVEVHNAK TKPREEQFNS 301 TYRVVSVLTV
LHQDWLNGKE YKCKVSNKGL PSSIEKTISK AKGQPREPQV 351 YTLPPSQEEM
TKNQVSLTCL VKGFYPSDIA VEWESNGQPE NNYKTTPPVL 401 DSDGSFFLYS
RLTVDKSRWQ EGNVFSCSVM HEALHNHYTQKSLSLSLG(K) The C-terminal lysine
is prone to clipping and might be present due to incomplete
clipping to a certain extent. The (K) in parenthesis is not part of
SEQ ID NO: 1. nBT062 light chain predicted sequence (SEQ ID NO: 2):
1 DIQMTQSTSS LSASLGDRVT ISCSASQGIN NYLNWYQQKP DGTVELLIYY 51
TSTLQSGVPS RFSGSGSGTD YSLTISNLEP EDIGTYYCQQ YSKLPRTFGG 101
GTKLEIKRTV AAPSVFIFPP SDEQLKSGTA SVVCLLNNFY PREAKVQWKV 151
DNALQSGNSQ ESVTEQDSKD STYSLSSTLT LSKADYEKHK VYACEVTHQG 201
LSSPVTKSFN RGEC
Table 5. shows a comparision of the general CDR definitions of
Krabat and Chothia and the predicted CDRs for nBT062
TABLE-US-00005 nBT062 Kabat CDR definition Light CDR1: residues
24-34 CDR1: residues 24-34 chain CDR2: residues 50-56 CDR2:
residues 50-56 CDR3: residues 89-97 CDR3: residues 89-97 Heavy
CDR1: residues 31-35 CDR1: residues 31-35 chain CDR2: residues
50-56 CDR2: residues 51-68 CDR3: residues 95-102 CDR3: residues
99-111 Chothia CDR definition Light CDR1: residues 26-32 CDR1:
residues 24-34 chain CDR2: residues 50-52 CDR2: residues 50-56
CDR3: residues 91-96 CDR3: residues 89-97 Heavy CDR1: residues
26-32 CDR1: residues 31-35 chain CDR2: residues 52-56 CDR2:
residues 51-68 CDR3: residues 96-101 CDR3: residues 99-111
Fully human antibodies may also be used. Those antibodies can be
selected by the phage display approach, where CD138 or an antigenic
determinant thereof is used to selectively bind phage expressing,
for example, B-B4 variable regions (see, Krebs, 2001). This
approach is advantageously coupled with an affinity maturation
technique to improve the affinity of the antibody. All antibodies
referred to herein are isolated antibodies (See US Patent
Publication 20090175863).
In one embodiment, the targeting antibody is, in its unconjugated
form, moderately or poorly internalized. Moderate internalization
constitutes about 30% to about 75% internalization of total
antibody, poor internalization constitutes about 0.01% to up to
about 30% internalization after 3 hours incubation at 37.degree. C.
In another preferred embodiment the targeting antibody binds to
CD138, for example, antibodies B-B4, BC/B-B4, B-B2, DL-101, 1 D4,
MI15, 1.BB.210, 2Q1484, 5F7, 104-9, 281-2 in particular B-B4.
Hybridoma cells, which were generated by hybridizing SP02/0 myeloma
cells with spleen cells of Balb/c mice have been deposited with the
DSMZ-Deutsche Sammlung von Mikroorganismen and Zellkulturen GmbH,
Mascheroder Weg 1, D-38124 Braunschweig on Dec. 11, 2007. The
identification number of these B-B4 expressing hybridoma cells is
DSM ACC2874. In another embodiment, the targeting antibody does not
substantially bind non-cell-surface expressed CD138. When, in the
context of the present invention, the name of a specific antibody
is combined with the term "targeting antibody" such as "nBT062
targeting antibody," this means that this targeting antibody has
the binding specificity of the antibody nBT062. If a targeting
antibody is said to be "based on" a specified antibody, this means
that this targeting antibody has the binding specificity of this
antibody, but might take any form consistent with the above
description of a targeting antibody. When, in the context of the
present invention, the name of a specific antigen is combined with
the term "targeting antibody" such as "CD138 targeting antibody,"
this means that this targeting antibody has binding specificity for
CD138. If, in the context of the present invention, for example, a
targeting antibody is said to do something "selectively" such as
"selectively targeting cell-surface expressed CD138" or, to be
"selective" for something, this means that there is a significant
selectivity (i.e. a higher affinity towards CD138-positive cells
compared with CD138-negative cells) for, in the case of the example
provided, cell-surface expressed CD138, compared to any other
cell-surface expressed antigen. Adverse side effects in a given
environment may be substantially reduced or even avoided due to
this selectivity.
"Non-immunoglobulin targeting molecules" according to the present
invention include targeting molecules derived from
non-immunoglobulin proteins as well as non-peptidic targeting
molecules. Small non-immunoglobulin proteins which are included in
this definition are designed to have specific affinities towards;
in particular, surface expressed CD138. These small
non-immunoglobulin proteins include scaffold based engineered
molecules such as AFFILIN molecules that have a relatively low
molecular weight such as between 10 kDa and 20 kDa. Appropriate
scaffolds include, for example, gamma crystalline. Those molecules
have, in their natural state, no specific binding activity towards
the target molecules. By engineering the protein surfaces through
locally defined randomization of solvent exposed amino acids,
completely new binding sites are created. Former non-binding
proteins are thereby transformed into specific binding proteins.
Such molecules can be specifically designed to bind a target, such
as CD138, and allow for specific delivery of one or more effector
molecules (see, scil Proteins GmbH at www.scilproteins.com, 2004).
Another kind of non-immunoglobulin targeting molecules are derived
from lipocalins, and include, for example ANTICALINS, which
resemble in structure somewhat immunoglobulins. However, lipocalins
are composed of a single polypeptide chain with 160 to 180 amino
acid residues. The binding pocket of lipocalins can be reshaped to
recognize a molecule of interest with high affinity and specificity
(see, for example, Beste et al., 1999). Artificial bacterial
receptors such as those marketed under the trademark Affibody.RTM.
(Affibody AB) are also within the scope of the present invention.
These artificial bacterial receptor molecules are small, simple
proteins and may be composed of a three-helix bundle based on the
scaffold of one of the IgG-binding domains of Protein A
(Staphylococcus aureus). These molecules have binding properties
similar to many immunoglobulins, but are substantially smaller,
having a molecular weight often not exceeding 10 kDa and are also
comparatively stable. Suitable artificial bacterial receptor
molecules are, for example, described in U.S. Pat. Nos. 5,831,012;
6,534,628 and 6,740,734.
Other "non-immunoglobulin targeting molecules" are physiological
ligands of the antigen in question. Physiological ligands of CD138
include for example, but not limited to, ADAMTS4 (aggrecanase-1),
antithrombin-3, bFGF, cathepsin G, CCL5 (RANTES), CCL7, CCL11,
CCL17, CD44, collagens (collagen type 1, collagen type 2, collagen
type 3, collagen type 4, collagen type 5, collagen type 6), CXCL1,
elastase, gp120, HGF [hepatocyte growth factor], laminin-1,
laminin-2, laminin-5, midkine, MMP-7, neutrophil elastase, and
pleiotrophin (HBNF, HBGF-8). Non-peptidic targeting molecules
include, but are not limited to, to DNA and RNA oligonucleotides
that bind to CD138 (aptamers).
An "effector molecule" according to the present invention is a
molecule or a derivative, or an analogue thereof which is attached
to a targeting agent, in particular a targeting antibody and/or an
engineered targeting antibody, and that exerts a desired effect,
e.g., apoptosis, or another type of cell death, or a continuous
cell cycle arrest on the target cell or cells. Effector molecules
according to the present invention include molecules that can exert
desired effects in a target cell and include, but are not limited
to, cytotoxic drugs, including low molecular weight cytotoxic drugs
(Molecular mass of less than 1500 Da, preferably less than 1400,
less than 1200, less than 1000, less than 800, less than 700, less
than 600, less than 500, less than 300 but generally more than 120
Da). These cytotoxic drugs are, according to the present invention,
generally non-proteinaceous biological cytotoxic drugs and contain
or induce, upon administration, the production of another cytotoxic
drug of at least 5 C atoms, 10 C atoms, preferably more than 12 C
atoms, often more than 20 C atoms and sometimes more than 30, 40 or
50 C atoms and generally at least one ring structure, such as a
benzene ring, which is often substituted. However, often
interconnecting ring structures are part of these molecules. These
non-proteinaceous biological cytotoxic drugs may intercalate into
DNA (DNA intercalators) or alkylate DNA, inhibit microtubule
formation, are inhibitors of mitosis, inhibitors of enzymes
involved in the structural integrity of DNA, such as histone
deacetylate or inhibitors of enzymes that are otherwise vital to a
cell and cause disruption of cell metabolism. Effectors can also be
categorized as radionuclides, biological response modifiers,
pore-forming agents, ribonucleases, proteins of apoptotic signaling
cascades with apoptosis-inducing activities, antisense
oligonucleotides, anti-metastatic agents, anti-oxidative
substances, antibodies or cytokines as well as functional
derivatives or analogues/fragments thereof.
In a preferred embodiment, the effector molecule increases internal
effector delivery of the immunoconjugate, in particular when the
natural form of the antibody on which the targeting antibody of the
immunoconjugate is based is poorly internalizable. In another
preferred embodiment the effector is, in its native form,
non-selective. In certain embodiments the effector has high
non-selective toxicity, including systemic toxicity, when in its
native form. The "native form" of an effector molecule of the
present invention is an effector molecule before being attached to
the targeting agent to form an immunoconjugate. In another
preferred embodiment, the non-selective toxicity of the effector
molecule is substantially eliminated upon conjugation to the
targeting agent. In another preferred embodiment, the effector
molecule causes, upon reaching the target cell, death or cell cycle
arrest, including continuous cell cycle arrest, in the target
cell.
An effector molecule according to the present invention includes,
but is not limited to, antineoplastic agents, in particular
intracellular chemotherapeutic agents, which are defined below.
TABLE-US-00006 Molecular mass Effector (g/mol [Da] Doxorubicin 564
Danurubicin 528 Vinblastin 811 Docetaxel 808 Paclitaxel 854
Epothilone B 508 Vorinostat 264 Neocarzinostatin 660 Calicheamicin
.gamma.1 1368 Esperamicin 1342 Methotrexate 454 Sylimarin 482
components Masoprocol 302 Aminolevulinic 132 acid Miltefosine 407
Epigallocatechin 459 gallate (EGCG) Psoralene 186 Melphalan 304
Table 6 provides examples of low molecular weight cytotoxic drugs
that may serve as effector molecules.
Low molecular weight cytotoxic drugs (see above for molecular
weights) may preferably be antimitotics, more particular, tubulin
affecting agents, which include inhibitors of tubulin
polymerization such as maytansinoids, dolastatins (and derivatives
such as auristatin) and crytophycin and potent taxoid (taxane)
drugs (Payne, 2003). Further included in the definition of small
highly cytotoxic drug are other tubulin interfering agents such as
epothilones (e.g. ixabepilone) and colchicine derivatives (tubulin
interfering agents are further discussed below).
An effector molecule that is a maytansinoid includes maytansinoids
of any origin, including, but not limited to synthetic maytansinol
and maytansinol analogue and derivative.
Maytansine is a natural product originally derived from the
Ethiopian shrub Maytenus serrata (Remillard, 1975; U.S. Pat. No.
3,896,111). This drug inhibits tubulin polymerization, resulting in
mitotic block and cell death (Remillard, 1975; Bhattacharyya, 1977;
Kupchan, 1978). The cytotoxicity of maytansine is 200-1000-fold
higher than that of anti-cancer drugs in clinical use that affect
tubulin polymerization, such as Vinca alkaloids or taxol. However,
clinical trials of maytansine indicated that it lacked a
therapeutic window due to its high systemic toxicity. Maytansine
and maytansinoids are highly cytotoxic but their clinical use in
cancer therapy has been greatly limited by their severe systemic
side-effects primarily attributed to their poor selectivity for
tumors. Clinical trials with maytansine showed serious adverse
effects on the central nervous system and gastrointestinal
system.
Maytansinoids have also been isolated from other plants including
seed tissue of Trewia nudiflora (U.S. Pat. No. 4,418,064)
Certain microbes also produce maytansinoids, such as maytansinol
and C-3 maytansinol esters (U.S. Pat. No. 4,151,042).
The present invention is directed to maytansinoids of any origin,
including synthetic maytansinol and maytansinol analogues which are
disclosed, for example, in U.S. Pat. Nos. 4,137,230; 4,248,870;
4,256,746; 4,260,608; 4,265,814; 4,294,757; 4,307,016; 4,308,268;
4,308,269; 4,309,428; 4,313,946; 4,315,929; 4,317,821; 4,322,348;
4,331,598; 4,361,650; 4,362,663; 4,364,866; 4,371,533; 4,424,219
and 4,151,042.
In a preferred embodiment, the maytansinoid is a thiol-containing
maytansinoid and is more preferably produced according to the
processes disclosed in U.S. Pat. No. 6,333,410 to Chari et al or in
Chari et al. (Chari, 1992).
DM-1 (N.sup.2-deacetyl-N.sup.2-(3-mercapto-1-oxopropyl)-maytansine)
is a preferred effector molecule in the context of the present
invention. DM1 is 3- to 10-fold more cytotoxic than maytansine, and
has been converted into a pro-drug by linking it via disulfide
bond(s) to a monoclonal antibody directed towards a
tumor-associated antigen. Certain of these conjugates (sometimes
called "tumor activated prodrugs" (TAPs)) are not cytotoxic in the
blood compartment, since they are activated upon associating with a
target cells and internalized, thereby releasing the drug (Blather,
2001). Several antibody-DM1 conjugates have been developed (Payne,
2003), and been evaluated in clinical trials. For example,
huC242-DM1 treatment in colorectal cancer patients was well
tolerated, did not induce any detectable immune response, and had a
long circulation time (Tolcher, 2003).
Other particularly preferred maytansinoids comprise a side chain
that contains a sterically hindered thiol bond such as, but not
limited to, maytansinoids
N.sup.2'-deacetyl-N.sup.2'-(4-mercapto-1-oxopentyl)-maytansine,
also referred to as "DM3," and
N.sup.2'-deacetyl-N.sup.2'-(4-methyl-4-mercapto-1-oxopentyl)-maytansine,
also referred to as "DM4." The synthesis of DM4 is shown in FIGS. 3
and 4 and is described elsewhere herein. DM4 differs from DM1 and
DM3 in that it bears methyl groups at its .alpha.C. This results in
a sterical hindrance when DM4 is attached via a linker in
particular, but not limited to, a linker comprising a disulfide
bond, to a targeting agent such as nBT062. A wide variety of
maytansinoids bearing a sterically hindered thiol group (possessing
one or two substituents, in particular alkyls substituents, such as
the methyl substituents of DM4) are disclosed U.S. Patent
Publication 2004/0235840, published Nov. 25, 2004, which is
incorporated herein in its entirety by reference. The steric
hindrance conferred by alkyl groups such as the methyl groups on
the carbon adjacent to the sulfur atom of DM3 and DM4 may affect
the rate of intracellular cleavage of the immunoconjugate. The
variable alkyl unit may therefore affect potency, efficacy, and
safety/toxicity in vitro and in vivo.
As reported by Goldmakher et al. in U.S. Patent Publication
2006/0233814, such a hindrance induces alkylation (e.g.,
methylation) of the free drug once the drug is released at its
target. The alkylation may increase the stability of the drug
allowing for the so-called bystander effect. However, as the person
skilled in the art will appreciate, other effector molecules
comprising substituents such as alkyl groups at positions that
result in a sterical hindrance when the effector is attached to a
targeting agent via a linker are part of the present invention
(U.S. Patent Publication 2004/0235840). Preferably this hindrance
induces a chemical modification such as alkylation of the free drug
to increase its overall stability, which allows the drug to not
only induce cell death or continuous cell cycle arrest in CD138
expressing tumor cells but, optionally, also to affect auxiliary
cells that, e.g., support or protect the tumor from drugs, in
particular cells of the tumor stroma and the tumor vasculature and
which generally do not express CD138 to diminish or lose their
supporting or protecting function.
Maytansine was evaluated in Phase I and Phase II clinical trials
sponsored by the National Cancer Institute (NCI) under IND #11,857
(submitted to FDA on Sep. 19, 1975). Both complete and partial
responses were seen in patients with hematological malignancies and
partial responses in patients with a broad spectrum of solid tumors
(Blum and Kahlert., 1978, Issell and Crooke, 1978, Chabner et al.,
1978, Eagan et al., 1978, Cabanillas et al., 1978). However,
significant toxicities, including nausea, vomiting, diarrhea,
elevations of liver function tests, lethargy, and peripheral
neuropathy were noted (see Maytansine IND #11,857, Annual Report,
February, 1984; Blum and Kahlert., 1978, Issell and Crooke, 1978,
Chabner et al., 1978). Toxic effects precluded further
development.
In another embodiment effector molecules might represent Taxanes.
Taxanes are a class of tubulin interfering agents (Payne 2003).
Taxanes are mitotic spindle poisons that inhibit the
depolymerization of tubulin, resulting in an increase in the rate
of microtubule assembly and cell death. Taxanes that are within the
scope of the present invention are, for example, disclosed in U.S.
Pat. Nos. 6,436,931; 6,340,701; 6,706,708 and United States Patent
Publications 20040087649; 20040024049 and 20030004210. Other
taxanes are disclosed, for example, in U.S. Pat. No. 6,002,023,
U.S. Pat. No. 5,998,656, U.S. Pat. No. 5,892,063, U.S. Pat. No.
5,763,477, U.S. Pat. No. 5,705,508, U.S. Pat. No. 5,703,247 and
U.S. Pat. No. 5,367,086. A preferred embodiment of the present
invention might be highly potent Taxanes that contain thiol or
disulfide groups. As the person skilled in the art will appreciate,
PEGylated taxanes such as the ones described in U.S. Pat. No.
6,596,757 are also within the scope of the present invention.
The present invention includes further DNA affecting effector
molecules, in more particular, intercalating agents such as
anthracyclines and derivatives (daunorubicin, valrubicin,
doxorubicin, aclarubicin, epirubicin, idarubicin, amrubicin,
pirarubicin, zorubicin) and anthracenediones, such as Streptomyces
derived substances (actinomycin, mitomycin, bleomycin,
aactinomycin) or amsacrine.
An effector molecule might represent more particular DNA alkylating
agents like, and more particular, Nitrogen mustard and analogues
(e.g. Cyclophosphamide, Melphalan, Estramustin), Alkylsulfonates,
Nitrosoureas, Aziridines, Hydrazines, Ethylene Imines, and other
substances such as Trenimon and Mitobronitol (a mannitol analogue).
In particular, preferred DNA alkylating agents are CC-1065
analogues or derivatives (U.S. Pat. Nos. 5,475,092; 5,585,499;
6,716,821) and duocarmycin.
CC-1065 represents a potent antitumor-antibiotic isolated from
cultures of Streptomyces zelensis and has been shown to be
exceptionally cytotoxic in vitro (U.S. Pat. No. 4,169,888). Within
the scope of the present invention are, for example, the CC-1065
analogues or derivatives described in U.S. Pat. Nos. 5,475,092,
5,585,499 and 5,739,350. As the person skilled in the art will
readily appreciate, modified CC-1065 analogues or derivatives as
described in U.S. Pat. No. 5,846,545 and prodrugs of CC-1065
analogues or derivatives as described, for example, in U.S. Pat.
No. 6,756,397 are also within the scope of the present invention.
In certain embodiments of the invention, CC-1065 analogues or
derivatives may, for example, be synthesized as described in U.S.
Pat. No. 6,534,660.
Other DNA alkylating effector molecules such as platinum based
substances are further included (e.g. e.g. carboplatin, nedaplatin,
oxaliplatin, triplatin, satraplatin).
Among the DNA affecting effector molecules, also Topoisomerase I
and II inhibitors are included, such as Camptotheca derived
substances (belotecan, topotecan) and Podophyllotoxin and
derivatives (etoposide, teniposide).
Further subclass of DNA affecting effector molecules include
antimetabolites such as folic acid analogues (methotrexate, known
as a dihydrofolate reductase inhibitors) or Aminopterin. Also
included are metabolites interfering with purine or pyrimidine
metabolism, in particular adenosine deaminase inhibitor
(pentostatin), or halogenated/ribonucleotide reductase inhibitors
(cladribine, clofarabine), thiopurine and tiazofurine. Further
antimetabolites include DNA polymerase inhibitor (cytarabine),
ribonucleotide reductase inhibitor (gemcitabine), and
hypomethylating agents (azacitidine, decitabine) and ribonucleotide
reductase inhibitors. More general included are also DNA
crosslinking substances such as cisplatin.
Effector molecules according to the present invention may be
antitumor antibiotics, defined as DNA modifying or damaging
effector molecules including enediyne antibiotics such as
calicheamicin which include, e.g., gamma 1l, N-acetyl calicheamicin
and other derivatives of calicheamicin. Calicheamicin binds in a
sequence-specific manner to the minor groove of DNA, undergoes
rearrangement and exposes free radicals, leading to breakage of
double-stranded DNA, resulting in cell apoptosis and death. One
example of a calicheamicin effector molecule that can be used in
the context of the present invention is described in U.S. Pat. No.
5,053,394. This compound is used in immunoconjugates with the
monoclonal antibodies published as gemtuzumab ozogamicin and
inotuzumab ozogamicin.
A subgroup of enediyne comprises the chromoproteins esperamycin and
neocarzinostatin. In particular, trabectedin, which is also
categorized as a DNA damaging agent (anti-tumor antibiotics)?
Trabectedin causes DNA backbone cleavage and can be isolated from a
sea squirt (also known as ecteinascidin 743 or ET-743) is sold by
ZELITA and JOHNSON & JOHNSON under the brand name YONDELIS.
Another group of preferred effector molecules are substances such
as, but not limited to, toxins affecting cell metabolism. In
particular enzyme inhibitors such as but not only, olaprib, or more
preferred proteasome (e.g. bortezomib) and protein kinase
inhibitors, or lipoxygenase inhibitors such as masoprocol are part
of the present invention. Also included are receptor antagonists
such as, but not limited to, endothelin A receptor antagonist (e.g.
atrasentan), or sex steroids such as testolactone, interfering with
estrone metabolism. Further included are estrogen receptor
interacting substances such as plant derived polyphenols, for
example but not only isoflavonoids, stilbenes, silymarin,
phenylpropanoid glycosides.
Also suitable as effector molecules are substances affecting cell
metabolism, such as substances used for photodynamic or radiation
therapy, including, but not limited to, porphyrin derivatives e.g.
.delta.-aminolevulinic acid. Efaproxiral represents a
radiosensitizer, which increases oxygen levels by decreasing
hemoglobin-oxygen affinity. Further included are retinoids (first,
second and third generation), in particular tretinoine, all trans
retinoic acid (ATRA), which is used to treat acute promyelocytic
leukemia (APML) sold for this indication by ROCHE under the brand
name VESANOID. Retinoids are a class of chemical compounds that are
related chemically to vitamin A, exerting diverse functions as for
example activation of tumor suppressor genes. At present they are
used to treat skin cancer and inflammatory skin disorders.
In another preferred embodiment, effector molecules might affect
signaling pathways, such as but not limited to, calcium signaling.
Examples are arsenic trioxide or trimethyltin chloride, the latter
of which is a highly toxic organotin compound.
The present invention also includes effector molecules that are
affecting drug resistance mechanisms which might include, for
example, anti-multidrug resistance activity (via P-glycoprotein
inhibition). Bicyclic heteroaromatic compounds and derivatives
might severe as non-limiting examples.
Another effector molecule class might include substances, or more
particular proteins interfering with apoptotic signaling pathways,
including, but not limited to, antisense oligonucleotides, more
particular, oligodeoxynucleotides such as oblimersen (INN, trade
name genasense; also known as augmerosen and bcl-2 antisense
oligodeoxynucleotide G3139) which is an antisense
oligodeoxyribonucleotide actually studied as a possible treatment
for several types of cancer, including chronic lymphocytic
leukemia, B-cell lymphoma, and breast cancer. It has been proposed
that this compound may kill cancer cells by blocking the production
of Bcl-2 and by rendering them more sensitive to chemotherapy.
Further apoptosis inducing classes of substances that may serve as
effector molecules comprise plant polyphenols such as, but not
limited to, silymarins, which are able to interfere with cell cycle
regulators and proteins involved in apoptosis
Effector molecules might also be proteins, such as those of
apoptotic signaling cascades with apoptosis-inducing activities,
including, but are not limited to, Granzyme B, Granzyme A,
Caspase-3, Caspase-7, Caspase-8, Caspase-9, truncated Bid (tBid),
Bax and Bak.
Other effector molecules might include enzymes such as but not
limited to, asparaginase or other enzymes with antineoplastic
activities.
A drug-effector molecule according to the present invention may
also be an antiprotozoal drug such as miltefosine.
In another embodiment effector molecules might represent plant
polyphenoles, such as, but not limited to, psoralens and their
hydroxy metabolites.
Plant polyphenoles such as flavonoids, tannins (proanthocyanidins),
stilbenoids, curcuminoids and ligands having one of the above
mentioned antitumor activities (e.g. apoptosis inducing, cell cycle
arrest) or additional activity such as free radical scavenging,
metal chelating activity, estrogen receptor interfering activity,
antioxidant, interfering with drug metabolizing enzymes are also
possible effector molecules. More specifically, psoralens and their
hydroxy metabolites which are able to intercalate into DNA acting
as metal chelators having antioxidant and cytoprotective properties
are preferred effector molecules. Particularly preferred are
reservatol and polyhydroxylated derivatives and flavonoids, such as
catechins and epicatechins, more specifically epigallocatechin 3-O
gallate, which may act as antioxidants.
Another embodiment of effector molecules might represent Toxins.
Toxins may include bacterial toxins, such as, but not limited to,
Diphtheria toxin or Exotoxin A, plant toxins, such as but not
limited to, Ricin other alkaloids and polyphenols, mycotoxins, such
as alpha amanitin or more specially Amatoxins and phallotoxins.
Toxins might not only be of bacterial origin, but also fungal,
plant, vertebrate and invertebrate origin, all of which can be
genetically or chemically modified. Moreover toxins might also be
environmental toxins such as, but not limited to, methylmercury.
Toxins may also be dolastatins 10 and 15 are small peptides
isolated from the marine sea hare Dolabella auricularia that have
been shown to interact with tubulin
A broad classification of effector molecules according to their
mechanism is also possible: Antineoplastic agents and
immunomodulating agents (According to ATC code L01) in particular
"Intracellular chemotherapeutic agents" ATC: Anatomical
Therapeutical Chemical classification system (WHO) 1) Antimitotics,
or molecules affecting microtubules (tubulin binding agents) such
as vinca alkaloids and analogues (Vinca alkaloids (Vinblastine,
Vincristine, Vinflunine, Vindesine, Vinorelbine) and taxanes
(Paclitaxel, Larotaxel, Docetaxel) dolastatins (and derivatives
e.g. auristatin) and crytophycin, maytansine and colchicine
derivatives, epothilones (e.g., ixabepilone) 2) affecting DNA
replication a) Intercalating agents such as anthracyclines
(Daunorubicin, Valrubicin, Doxorubicin, Aclarubicin, Epirubicin,
Idarubicin, Amrubicin, pirarubicin, Zorubicin) and
Anthracenediones, such as Streptomyces derived substances
(Actinomycin, Mitomycin, Bleomycin, Dactinomycin) or Amsacrine b)
Alkylating agents such as Nitrogen mustards, Nitrosoureas,
Alkylsulfonates, Aziridines, Hydrazines (Procarbazine), Triazenes,
Epoxides, Ethylene Imines, Altretamine, Mitobronitol, duocarmycin
and analogues/stereoisomers, Trenimon, Estramustine, CC-1065 c)
Alkylating-like agents such as Platinum (e.g. Carboplatin
Nedaplatin, Oxaliplatin, Triplatin Tetranitrate, Satraplatin) d)
Topoisomerase I specific inhibitors such as camptotheca (Belotecan,
Topotecan) e) Topoisomerase II specific inhibitors such as
Podophyllotoxin and derivatives (Etoposide, Teniposide) f)
Antimetabolites affecting DNA/RNA synthesis by interfering with
folic acid such as Dihydrofolate reductase inhibitors (e.g.
Aminopterin, Methotrexate), thymidilate synthase inhibitor purine
such as adenosine deaminase inhibitor (Pentostatin),
halogenated/ribonucleotide reductase inhibitor (Cladribine,
Clofarabine), Thiopurine, Tiazofurine Pyrimidine such as DNA
Polymerase inhibitor (Cytarabine), ribonucleotide reductase
inhibitor (Gemcitabine), hypomethylating agent (Azacitidine,
Decitabine) deoxyribonucleotide such as ribonucleotide reductase
inhibitor Hydroxycarbamid g) other DNA crosslinking agents such as
platinum based compounds (e.g. Cisplatin) 3) Other DNA interfering
substances e.g. "antitumor/cytotoxic antibiotics" such as elsamicin
A, further antibiotics such as CC-1065, and subclasses of
antibiotics such as bacteria derived enediyne chalicheamin or
chromoprotein enediyne esperamicin (extremely toxic DNA splicing
agent) or neocarzinostatin (other members of the neocarzinostatin
group of antibiotics are macromomycin, actinoxanthin, kedarcidin
and maduropeptin.) or Trabectedin (DNA backbone cleavage) 4) toxins
affecting cell metabolism e.g. HSP90 inhibitors, Lonidamide
(inhibits both respiration and glycolysis leading to a decrease in
cellular ATP) a) Enzyme inhibitors e.g. Olaprib (PARP inhibitor),
CDK inhibitors (Alvocidib), Proteasome (Bortezomib), Protein kinase
inhibitors, Masoprocol (Lipoxyenase inhibitor) b) Receptor
antagonists such as tutin (Glycin receptor antagonist (plant
toxin), Atrasentan, retinoid X receptor (Bexarotene), sex steroids
such as testolactone, estrogen receptor interfering substances c)
Photosensitizers or other compounds used for photodynamic therapy
(Porfirmer Sodium), Porphyrin derivatives e.g.
.delta.-Aminolevulinic acid) d) Radiosensitizer such as Efaproxiral
which increases oxygen levels by decreasing hemoglobin-oxygen
affinity e) Substances affecting signaling pathways e.g. Ca.sup.2+
signaling such as arsenic trioxide and trimethyltin chloride f)
Other substances interfering with metabolism such as retinoids and
derivatives Tretinoine (ATRA) 5) Affecting epigenetic processes
such as HDAC inhibitors (e.g. Panobinostat, Vorinostat, Valporic
acid, MGCD0103 (Mocetinostat), which are at present in clinical
development for cutaneous T-cell lymphoma, acute myeloid leukemia,
Hodgkin lymphoma or follicular lymphoma) 6) Affecting drug
resistance mechanisms such as bicyclic heteroaromatic compounds,
which inhibit P-glycoprotein 7) Substances inducing apoptotic
signaling/mechanisms include proteins but also antisense
oligodeoxynucleotides such as Oblimersen (trade name Genasense) 8)
Enzymes such as Asparaginase 9) Antiprotozoal drugs such as
Miltefosine 10) Plant polyphenoles such as Flavonoids, Tannins
(Proanthocyanidins), Stilbenoids, curcuminoids and lignans having
one of the above mentioned antitumor activities (e.g. apoptosis
inducing, cell cycle arrest) or additional activity such as free
radical scavenging, metal chelating activity, estrogen receptor
interfering activity, antioxidant, interfering with drug
metabolizing enzymes). More specifically psoralens and their
hydroxy metabolites, reservatol and polyhydroxylated derivatives,
Flavonoids, such as Catechins and Epicatechins, more specifically
epigallocatechin 3-O gallate 11) Further natural substances and
derivatives such as exotoxin A, diphtheria toxin, and derivatives
thereof, wherein the derivatives can be chemically or genetically
modified.
Effector molecules can also be categorized according to the
substance class they belong to such as anorganic compounds,
aromatic compounds, metal based compounds, proteins related to cell
metabolism, enzymes, peptides, oligonucleotides, such as antisense
nucleotides, bacterial toxins, plant derived toxins and polyphenols
such as tannins, flavonoids and coumarins as well as terpenoids,
alkaloids, anti-tumor antibiotics (e.g. enediyne antibiotics),
mycotoxins, toxins from invertebrates as well as vertebrates,
environmental toxins.
An immunoconjugate according to the present invention comprises at
least one targeting agent, in particular targeting antibody and one
effector molecule. The immunoconjugate might comprise further
molecules for example for stabilization. For immunoconjugates, the
term "conjugate" is generally used to define the operative
association of the targeting agent with one or more effector
molecules and is not intended to refer solely to any type of
operative association, and is particularly not limited to chemical
"conjugation". So long as the targeting agent is able to bind to
the target site and the attached effector functions sufficiently as
intended, particularly when delivered to the target site, any mode
of attachment will be suitable. The conjugation methods according
to the present invention include, but are not limited to, direct
attachment of the effector molecule to the targeting antibody, with
or without prior modification of the effector molecule and/or the
targeting antibody or attachment via linkers. Linkers can be
categorized functionally into, for example, acid labile,
photolabile linkers, enzyme cleavable linkers, such as linkers that
can be cleaved by peptidases. Cleavable linkers are preferred in
many embodiments of the invention. Such cleavable linkers can be
cleaved under conditions present in the cellular environment, in
particular, an intracellular environment with no detrimental effect
on the drug released upon cleavage. Low pHs such as pH of 4 to 5,
as they exist in certain intracellular departments, will cleave
acid labile linkers, while photolabile linkers can be cleaved by,
e.g., infrared light. However, linkers that are cleaved by/under
physiological conditions present in the majority of cells are
preferred and are referred to herein as physiologically cleavable
linkers. Accordingly, disulfide linkers are preferred in many
embodiments of the invention. These linkers are cleavable through
disulfide exchange, which can occur under physiological conditions.
Preferred heterobifunctional disulfide linkers include, but are not
limited to, N-succinimidyl 3-(2-pyridyldithio)propionate (SPDP)
(see, e.g., Carlsson et al. (1978)), N-succinimidyl
4-(2-pyridyldithio)butanoate (SPDB) (see, e.g., U.S. Pat. No.
4,563,304), N-succinimidyl 4-(2-pyridyldithio)pentanoate (SPP)
(see, e.g., CAS Registry number 341498-08-6), N-succinimidyl
4-(N-maleimidomethyl)cyclohexane-1-carboxylate (SMCC) (see, e.g.,
Yoshitake et al., (1979)), and N-succinimidyl
4-methyl-4-[2-(5-nitro-pyridyl)-dithio]pentanoate (SMNP) (see,
e.g., U.S. Pat. No. 4,563,304). The most preferred linker molecules
for use in the inventive composition are SPP, SMCC, and SPDB.
Other suitable linkers may include "non-cleavable" bonds, such as,
but not limited to Sulfosuccinimidyl maleimidomethyl cyclohexane
carboxylate (SMCC), which is a heterobifunctional linker capable of
linking compounds with SH-containing compounds. Bifunctional and
heterobifunctional linker molecules, such as carbohydrate-directed
heterobifunctional linker molecules, such as
S-(2-thiopyridyl)-L-cysteine hydrazide (TPCH), are also within the
scope of the present invention (Vogel, 2004). The effector
molecule, such as a maytansinoid, may be conjugated to the
targeting antibody via a two reaction step process. This includes
as a first step the modification of the targeting antibody with a
cross-linking reagent such as N-succinimidyl
pyridyldithiopropionate (SPDP) to introduce dithiopyridyl groups
into the targeting antibody. In a second step, a reactive
maytansinoid having a thiol group, such as DM1, may be added to the
modified antibody, resulting in the displacement of the thiopyridyl
groups in the modified antibody, and the production of
disulfide-linked cytotoxic maytansinoid/antibody conjugate (U.S.
Pat. No. 5,208,020). However, one-step conjugation processes such
as the one disclosed in United States Patent Publication
20030055226 to Chari et al are also within the scope of the present
invention. In one embodiment of the present invention multiple
effector molecules of the same or different kind are attached to a
targeting antibody. As discussed elsewhere herein, the nature of
the linkers employed may influence bystander killing (Kovtun et
al., 2006). See also U.S. Pat. Nos. 5,208,030; 5,416,064;
6,333,410; 6,441,163; 6,716,821; 6,913,748; 7,276,497 and US
Application No. 2005/0169933 for method for preparing
immunoconjugates.
CC-1065 analogues or derivatives may be conjugated to the targeting
agent via, for example, PEG linking groups as described in U.S.
Pat. No. 6,716,821.
Calicheamicins may be conjugated to the targeting antibodies via
linkers (U.S. Pat. No. 5,877,296 and U.S. Pat. No. 5,773,001) or
according to the conjugation methods disclosed in U.S. Pat. No.
5,712,374 and U.S. Pat. No. 5,714,586. Another preferred method for
preparing calicheamicin conjugates is disclosed in Unites States
Patent Publication 20040082764. The immunoconjugates of the present
invention may take the form of recombinant fusion proteins.
Operational association in form of an attachment with or without a
linker is referred to herein as "functional attachment."
One milligram (mg) of immunoconjugate BT062 comprises approx. 3.5
DM4 molecules (1 DM4 has an approximate molecular weight of 800
Da), thus 1 mg immunoconjugate comprises 2800 Da of DM4.
The molecular weight of BT062 is about 150000 Da. Thus, 1 mg
immunoconjugate comprises about 1/53 mg DM4 molecules. Thus 4 mg/ml
of antibody corresponds to about 4/53 DM4 molecules, which is 75
.mu.g/ml. 160 mg/m.sup.2 of immunoconjugate corresponds to about
2.5 to 3.5, in particular to about 3 mg/m.sup.2 of DM4.
According to the present invention more than 2, 2.5, 3, 3.5 or even
4 mg/m.sup.2 DM4 can be administered to a subject in either
repeated single doses or multiple doses, including repeated
multiple doses, without DLTs.
An immunoconjugate consisting essentially of certain components
means in the context of the present invention that the
antibody/immunoconjugate consists of the specified components and
any additional materials or components that do not materially
affect the basic characteristics of the antibody.
Some of the immunoconjugates of the present invention have an
effector molecule that is sterically hindered and contains a
cleavable linker (HICL--hindered immunoconjugate, cleavable
linker). An unhindered counterpart (UI: unhindered immunoconjugate)
of an immunoconjugate comprising an engineered targeting antibody
against CD138 attached to an effector molecule via a cleavable
linker (CL) and is described herein as UICL. The UICL is an
immunoconjugate equivalent to the HICL comprising an engineered
targeting antibody in which the effector molecule is, however, not
sterically hindered. Examples of a pair of HICL/UICL are BT062 and
nBT062-SPP-DM1. An unhindered counterpart of such an
immunoconjugate comprising a non-cleavable linker (UINCL) refers to
the equivalent immunoconjugate comprising an engineered targeting
antibody in which the effector molecule is not sterically hindered
and comprises a noncleavable linker. For BT062 (nBT062-SPDB-DM4),
nBT062-SMCC-DM1 would constitute an example of such an unhindered
counterpart comprising a non-cleavable linker (UNICL).
A growth of a tumor inhibiting activity (=tumor growth inhibiting
activity) of an immunoconjugate is a relative measure. It describes
the tumor growth inhibiting activity of a conjugate relative to the
activity of the highest performing immunoconjugate whose activity
is set as 100%. For example, if the activity of the highest
performing immunoconjugate, say, BT062, which causes a tumor growth
delay (TGD) of 32 days, is set as 100%, the activity of, e.g.,
nBT062-DM1, which displays a tumor growth delay (TGD) of 18 days is
calculated as follows: Tumor Growth Inhibiting
Activity=100.times.(TGD.sub.nBT062-DM1/TGD.sub.BT062), more
generically: Tumor Growth Inhibiting
Activity=100.times.(TGD.sub.Sample/TGD.sub.Reference).
TABLE-US-00007 TABLE 7 Tumor growth delay (TGD) and % Activity of
nBT062-DMx against MOLP-8 tumor xenografts in SCID mice based on
treatment groups receiving a 450 .mu.g/kg dose. TGD* (days) %
Activity** PBS 0 0 nBT062-SMCC-DM1 18 56 BT062 32 100
nBT062-SPP-DM1 13 40 *Tumor growth delay in days (TGD) as mean time
in days for treatment group to reach a predetermined size (160
mm.sup.3) minus the mean time for the control group to reach this
predetermined size. **Tumor Growth Inhibiting Activity = 100
.times. (TGD.sub.Sample/TGD.sub.BT062). The activity of BT062 is
defined to be 100%.
In the example provided in Table 7, BT062 provides a growth of a
tumor inhibiting activity that exceeds that of its unhindered
counterpart (nBT062-SPP-DM1) by 60%, and a growth of a tumor
inhibiting activity that exceeds that of its unhindered counterpart
immunoconjugate comprising a non-cleavable linker (nBT062-SMCC-DM1)
by 44%.
As discussed above, certain drugs such as maytansinoids, while
effective, are highly toxic, destroying in their native, i.e.,
unconjugated form, cells non-selectively. Linking the cytotoxic
maytansinoid to an antibody can keep the drug inactive until it
reaches the target cell (Lambert 2005). Several
antibody-maytansinoid conjugates have undergone clinical
development.
Phase I and II studies with IMGN901 (huN901-DM1, BB-10901) for
treating CD56-positive solid tumors (small cell lung cancer and
neuroendocrine cancers) were performed. In these studies IMGN901
was administered on 4 consecutive weeks every 6 weeks and was
generally well tolerated (Fossella et al., 2005, Lorigan et al.,
2006, McCann et al., 2007, Carter and Senter, 2008, Johnson et al.
2008). The antibody portion of the immunoconjugate, huN901, shows
significant CDC or ADCC activity. The same immunoconjugate is
investigated for treatment of CD56-positive multiple myeloma. In a
phase I study administration of IMGN901 on 2 consecutive weeks
every 3 weeks to patients with CD56-positive multiple myeloma who
have failed established multiple myeloma treatments has shown
preliminary evidence of safety as well as clinical activity.
Eighteen patients were reported to have received IMGN901 (3
patients each at 40, 60, 75, 90, 112, and 140 mg/m.sup.2/week).
Preliminary pharmacokinetic (PK) results were reported to indicate
an approximately linear relationship between dosing and observed
maximal serum concentration. Interesting clinical activity has been
observed with a tolerable safety profile. A confirmed minor
response (MR) was documented in 3 heavily pretreated patients (1
patient each at 60, 90, and 112 mg/m.sup.2/week) using the European
Bone Marrow Transplant criteria. Durable stable disease was
reported at doses of 60, 90, 112, and 140 mg/m.sup.2/week
(Chanan-Khan et al., 2007, Chanan-Khan et al., 2008). IMGN901 at a
dose of 75 mg/m.sup.2/week will be taken forward for further
investigation in the expansion phase of the trial. At higher doses,
peripheral neuropathy was reported with the treatment combination
with lenalidomide and dexamethasone, the standard treatment regimen
for multiple myeloma.
MLN2704 (huJ591-DM1) is investigated for treating
castration-resistant prostate cancer (Milowsky et al., 2006, Brand
and Tolcher 2006). A Phase I trial of MLN2704 in patients with
progressive metastatic castration-resistant prostate cancer
investigated the safety profile, pharmacokinetics, immunogenicity,
and antitumor activity of MLN2704 when administered once every four
weeks. Results demonstrated that therapeutic doses of MLN2704 can
be administered safely on a repetitive basis (Galsky et al., 2008).
Parallel trials were performed with another DM1-immunoconjugate,
namely bivatuzumab mertansine which targets CD44v6, which is
expressed on head and neck carcinomas and other solid tumors. In
the clinical trial with the most condensed administration schedule
(weekly administration) binding to CD44v6 on skin keratinocytes
mediated serious skin toxicity with a fatal outcome in one patient,
which led to the termination of the development program of
bivatuzumab mertansine (Tijink et al., 2006, Sauter et al., 2007,
Rupp et al., 2007, Riechelmann et al., 2008).
CD44v6 is not only expressed on various cancer cells, but also in
normal skin tissue and resembles in this respect CD138 which is
also expressed not only on cancer cells but in normal skin tissue.
Surprisingly, it was found that BT062 shows clinical efficacy
without intolerable side effects like skin toxicity as found in
bivatuzumab mertansine. See FIG. 28, which shows that repeated
single doses BT062 of up to 160 mg/m.sup.2 led to at least stable
disease with manageable side effects over extended periods of time.
The figure in particular shows a minor response defined by serum
M-protein (M-protein levels were reduced by .gtoreq.25%). Only
after a hold period (days 400 to 421) did the M-protein levels
increase, but could be stabilized after the next dose was received.
In sum, there was progression free survival for about 22 months,
with a duration of a minor response for 19 months. It was also
previously shown that 10 repeated single doses of 20 mg/m.sup.2
(treatment over more than 6 months), 5 repeated single doses of 40
mg/m.sup.2, 5 repeated single doses of 80 mg/m.sup.2, 6 repeated
single doses of 160 mg/m.sup.2, and 1 single doses of 200
mg/m.sup.2 followed by 6 repeated single doses of 160 mg/m.sup.2
(ergo, a total dose of 1160 mg/m.sup.2) were well tolerated (See
also US Patent Publication 20110123554).
CD138 is also expressed on normal blood cells and other cells whose
destruction would lead to intolerable side effects, ergo severe
adverse events (SAES) discussed later herein. Irrespective of this,
no dose limiting toxicity towards non-cancer/non-tumor cells
expressing CD138 of any sort were found in the repeated single dose
treatment regimens up to 120 mg/m.sup.2. An aggregate dose of 360
mg/m.sup.2 resulted in 3 weeks (21 days) when 120 mg/m.sup.2 was
administered ion day 1, 8, and 15 and a resting period of 1 week.
Thus, while the aggregate maximum tolerable dose (AMTD) in the
context of this once a week treatment regime is higher than the
maximum tolerable dose (MTD) which, in the case of BT062, has
previously been determined to be 160 mg/m.sup.2 when the
immunoconjugate was only administered as a single dose, here on day
one in a 21 day cycle. In fact, the AMTD is higher, including more
than 50%, 60%, 70%, 80%, 90%, 100% higher than the previously
determined dose limiting toxicity (DLT), in the case of BT062, 200
mg/m.sup.2 for administration of the immunoconjugate as a single
dose, e.g., once, e.g. on day 1, in a three week (21 days) active
treatment cycle. This constitutes a significant difference to other
immunoconjugates, where no difference in the DLT or MTD could be
found between an administration of the immunoconjugate as a single
dose (including repeated single dose), e.g., a one time
administration within three weeks and in multiple dose regimen,
e.g., a three time administration once a week for three weeks (21
days).
The effects aggregate maximum tolerable dose (AMTD) are identical
to the effects of an MTD defined elsewhere herein. However, the
term "aggregate" conveys that the administration is not performed
as a single dose or repeated single dose within a certain time
period, e.g. an active treatment cycle of, e.g., three weeks (e.g.,
21 days), but that, within said certain time period, the
immunoconjugate is administered in intervals, e.g., weekly
intervals such as on day 1, 8 and 15 of a 21 day period.
Preferably, equal doses are administered, e.g., in 7 day intervals
(e.g., day 1, 8 and 15), 3 day intervals (e.g., day 1, 4, 7, 10, 13
and 16), 4 day intervals, 5 day intervals or 6 day intervals.
However, slight variation in the administrations such as an initial
booster administration described elsewhere herein are also within
the scope of the present invention. The administration intervals
may be increased or decreased after each cycle (see also
maintenance therapy discussed elsewhere herein). For example, the
first and optional second cycle might involve administration every
3.sup.rd day, while in the following cycles the intervals may be,
e.g., progressively, increased to 4, 5, 6 or 7 days. A fraction of
a of the AMTD includes e.g. about 95% of the AMTD, about 90% of the
AMTD, about 85%, about 80%, about 75% about 70%, about 65%, about
60%, about 55%, about 50%, about 45% of the AMTD. Assuming, e.g.,
that the AMTD of a theoretical immunoconjugate is 100 mg/m.sup.2, a
95% fraction would be, e.g., 95 mg/m.sup.2.
Adverse events (AEs) can be evaluated according to the NCI-CTCAE
version 4.0 (Cancer Therapy Evaluation Program, Common Terminology
Criteria for Adverse Events, Version 3.0, DCTD, NCI, NIH, DHHS Mar.
31, 2003), National Cancer Institute, US National Institutes of
Health, Publishing Date: Aug. 9, 2006). For AEs not listed in the
CTCAE v4.03, severity will be assessed by the Investigator by the
following criteria:
Only grade 1 and grade 2 AEs are acceptable, whereby Grade 1 (Mild)
requires minimal or no treatment and does not interfere with the
patient's daily activities and Grade 2 (Moderate) results in a low
level of inconvenience or concern with the therapeutic measures.
Moderate events may cause some interference with the subject's
functioning.
AEs of Grade 3 (Severe) and Grade 4 (Life threatening) are
considered not acceptable their occurrence defines the DLT (dose
limiting toxicity), if not otherwise defined by study specific DLT
criteria (see below).
AEs of Grade 3 and 4 are also referred to as severe adverse events
(SAE) and include lymphopenia, leucopenia, thrombopenia,
neutropenia, cardiac arrest, atrial fibrillation, pulmonary
embolism and deep vein thrombosis. Other study specific criteria
may be employed (see below).
Dose limiting toxicities (DLT) are determined using the grading
according to NCI CTCAE v4.0 referenced to above. Generally, all
toxicities of at least grade 3 are defined as DLT. Further study
specific DLT criteria which can be employed are listed below:
Nonhematological:
Alopecia, of any grade, is not considered a DLT Grade 3-4 nausea
and vomiting lasting longer than 3 days despite optimal antiemetic
medication..sup.a Grade 3-4 diarrhea lasting longer than 3 days
despite optimal antidiarrheal medication..sup.a a. Optimal
antidiarrheal and antiemetic treatment were determined by each
investigator. Hematologic: Grade 4 neutropenia lasting longer than
5 days. Grade 3 or higher neutropenia with temperature greater than
or equal 101.degree. F., for 2 consecutive determinations spaced 4
hours apart. Grade 4 thrombocytopenia Grade 3 or higher
thrombocytopenia with bleeding and requiring the use of platelet
transfusion. Grade 3 neutropenia, grade 3 thrombocytopenia were NOT
considered DLTs.
The maximum tolerated dose (MTD) is defined as the dose at which
any subject to whom a single dose or a repeated single dose has
been administered experiences dose limiting toxicities (DLTs). As
is readily apparent, a MTD can be readily determined for a wide
variety of immunoconjugates according to the present invention.
These DLTs may occur in a first or a subsequent treatment cycle. In
particular, 1 out of 6 subjects to whom a single dose or a repeated
single dose has been administered experience DLTs. Preferably DLTs
in the first cycle are considered.
During dose escalations, preferably only DLTs in the first cycle
are considered.
Study Specific Adverse Event (AE)
Any unfavorable or unintended sign, symptom, or disease that
appears or worsens in a patient or clinical investigation subject
during the period of observation in a clinical study. The AE may be
any of the following: a new illness an exacerbation of a sign or
symptom or the underlying condition under treatment or of a
concomitant illness, unrelated to participation in the clinical
study or an effect of the study medication or comparator drug, a
combination of one or more of the above factors.
Generally, no causal relationship with the study medication is
implied by the use of the term "adverse event".
Serious Adverse Event (SAE)
An SAE is any untoward medical occurrence or effect that at any
dose: results in death, death is an outcome of an AE and not an AE
in itself. All deaths, regardless of cause or relationship must be
reported for patients on study is life-threatening,
life-threatening means that the patient was at immediate risk of
death from the event as it occurred. This does not include an event
that might have led to death if it had been more severe results in
persistent or significant disability or incapacity, is a congenital
anomaly or birth defect, or is another medically important
condition An important medical event that is not immediately
life-threatening or will result in death or hospitalization, but
which may jeopardize the patient/subject or may require medical
intervention to prevent one of the outcomes listed above, should be
reported as "serious" as well Causality of Adverse Event
Refers to the relationship of the AE to investigational product.
Causality will be categorized according to the following
criteria:
Not Related
AEs for which a reasonable explanation for an alternative cause is
considered plausible, e.g., non investigational product taken,
plausible clinical alternative like accidental injury, expected
progression of underlying or concomitant disease, pharmacologically
incompatible temporal relationship, intercurrent illness
Related
AEs for which a reasonably possible clinical and/or pharmacological
relationship to investigational product cannot be excluded, e.g.
lacking plausible alternatives.
Phase I studies with the immunoconjugated form of trastuzumab
(T-DM1) for treatment of HER2 over-expressing metastatic breast
cancer are performed to investigate safety and pharmacokinetics of
T-DM1 administered weekly or once every 3 weeks. In both studies
AEs of grade .gtoreq.2 related to T-DM1 have been infrequent and
manageable. Objective tumor responses have been observed at doses
at or below the MTD (Burris et. al., 2006, Krop et al., 2007,
Beeram et al., 2008, Holden et al., 2008). A phase II study
investigating T-DM1 in HER2-positive metastatic breast cancer when
administered once every 3 weeks has been initiated (Beeram et al.,
2008, Carter and Senter, 2008, Holden et al., 2008). A Phase III
clinical trial evaluating T-DM1 for second-line HER2-positive
metastatic breast cancer and Phase II clinical trials evaluating
T-DM1 for first-, second- and third-line HER2-positive metastatic
breast cancer are ongoing. A Phase lb clinical trial in combination
with pertuzumab for HER2-positive metastatic breast cancer patients
who have been progressed on Herceptin-based treatment is planned.
Three phase I clinical trials have been completed with cantuzumab
mertansine, a DM1-conjugate of the huC242 antibody that targets an
antigen found on colorectal cancers and other C242-expressing
cancers. Treatment with huC242-DM1 administered on a weekly basis
as well as once every 3 weeks was found to be safe and tolerated
(Rowinsky et al., 2002, Tolcher et al., 2003, Helft et al., 2004).
Four studies are investigating immunoconjugates using the
thiol-containing DM4 maytansinoid, which is also a component of
BT062:
An analog of cantuzumab mertansine, IMGN242 (huC242-DM4), was
investigated in a phase I study in subjects with CanAg-expressing
cancer (Tolcher et al., 2006). Subjects received a single IV
infusion of IMGN242 once every 3 weeks with a dose ranging from 18
to 297 mg/m.sup.2. Dose-limiting toxicity was experienced by 2 of 6
subjects treated at the 223 mg/m.sup.2 dose level during their
second cycle of treatment. The drug was well tolerated at the 168
mg/m.sup.2 level and did not induce any detectable antibody
response (Mita et al., 2007). Based on first safety results from
the Phase I study, a Phase II study was initiated to evaluate
IMGN242 for treating CanAg-expressing gastric cancer at the dose of
168 mg/m.sup.2 (Sankhala et al., 2007). Forty-five patients have
been treated with IMGN242 in two clinical trials. Based on the
safety and thorough clinical pharmacokinetic (PK)/pharmacodynamic
(PD) analyses, the Phase II study was amended to treat patients
with low plasma CanAg levels at the dose of 126 mg/m.sup.2 and
patients with high plasma CanAg levels at 168 mg/m.sup.2 (Qin et
al. 2008). A phase I study with huMy9-6 antibody conjugated to DM4
(AVE9633) was also performed for the treatment of subjects with
CD33-positive Acute Myeloid Leukemia (AML). The treatment regimen
consisted of IV infusions once every 3 week using a dose range of
15 to 260 mg/m.sup.2. Neither associated myelosuppression nor
responses have been noted in a single-dose study (Giles et al.,
2006). A second phase I study investigating AVE9633 with a
treatment regimen consisting of IV infusions on day 1 and day 8 of
a 28-day cycle also shows that AVE9633 was well tolerated; it also
provides evidence of antileukemia activity including 1 subject with
complete response (inadequate platelet response, transfusion
dependent) lasting for at least 4 months (Legrand et al., 2007).
Two further DM4-immunoconjugates (SAR3419 and BIIB015) have entered
into clinical trials.
SAR3419 (huB4-DM4) is an antibody-drug conjugate composed of a
humanized IgG1 monoclonal antibody, huB4, which specifically
targets the CD19 antigen, conjugated through a disulfide link to
the maytansinoid derivative DM4. Expression of the CD19 molecule is
found on all B lymphocytes, including pro-B cells, but is lost
during maturation to plasma cells. The CD19 antigen is also
expressed on the membrane of follicular dendritic cells and on most
stabilized B cell lines. After binding to the CD19 antigen, SAR3419
undergoes internalization and intracellular release of DM4. In a
phase I/II study SAR3419 was administered by intravenous infusion,
weekly with 8 to 12 doses, to patients with relapsed/refractory
B-cell NHL expressing CD19. Forty-four patients were enrolled at 7
dose levels from 10 to 70 mg/m.sup.2. Main histologies were
follicular (18; 41%) and diffuse large B-cell (17; 39%). The median
number of prior regimens was 3 (1-8) and 19 patients had received
prior transplantation. Twenty-eight patients were enrolled in the
dose escalation part. Of 6 patients at 70 mg/m.sup.2, 1 patient had
a protocol defined dose limiting toxicity (DLT) of neutropenia and
2 patients had grade 2 significant toxicities with late onset:
blurred vision associated with corneal deposits and left bundle
branch block. The maximum tolerated dose (MTD) was defined at 55
mg/m.sup.2, while the MTD in a regimen involving a single
administration every three weeks was 160 mg/m.sup.2. Of 22 patients
at the MTD of 55 mg/m.sup.2, 4 patients had related reversible
grade 3-4 toxicities after 6-8 doses: optic neuropathy,
paraesthesia, neutropenia and thrombocytopenia. Of 38 patients at
doses of 20 mg/m.sup.2 or higher, 12 (32%) patients achieved an
objective response including 6 CR/CRu (complete response/complete
response unconfirmed), with no obvious dose effect. Of 22 patients
at the MTD (55 mg/m.sup.2), 8 (36%) had a response, including 3
CR/CRu. Of 9 patients evaluable for response duration (RD), 4
patients had a RD ranging from 6 to at least 12 months. In sum it
can be said that the aggregate maximum tolerated dose (AMTD) in a
three weeks (21 days) dosing regimen involving 3 doses did not
exceed the MTD in a three weeks (21 days) dosing regimen involving
a single dose (e.g., on day one).
TABLE-US-00008 TABLE 8 Comparison of Immunoconjugates administered
in repeated multiple dose regimens (once weekly). Corresponds to
total concentration of (assuming 70 kg Once weekly and 1.9 m.sup.2
body regimens surface area) BT062 MTD 140 mg/m.sup.2 266 mg SGN-35
Up to 1.2 mg/kg 84 mg (Batlett et al., 2008) SAR3419 MTD 55
mg/m.sup.2 110 mg (Coiffer et al., 2011) T-DM1 MTD at 2.4 mg/kg 168
mg (Holden et al., 2008) SGN-75 (anti-CD70; MMAF) Study 0.3 to 0.6
mg/kg (SEATTLE GENETICS) (MTD has not been reached)
As can be seen from the table above, BT062 can be administered at
higher doses once weekly (at least in total an amount of 266 mg).
In contrast to the other immunoconjugates listed, BT062 displayed
characteristic pharmacokinetics. In particular BT062 shows a
characteristic discrepancy between observed and theoretical Cmax
values BT062 described elsewhere herein.
Also, it is known from other immunoconjugates, such as Mylotarg
which is targeting CD33, that the activity of the immunoconjugate
may not be sufficient to treat patients at low doses. This problem
has been alleviated by, e.g., administration of recombinant human
granulocyte colony-stimulating factor (rhG-CSF) to sensitize CD33
expressing target cells (Fianchi et al., Annals of Oncology 2008
19(1):128-134).
The above studies demonstrate that the responses to different
immunoconjugates, in particular maytansinoid (such as DM1 or DM4)
containing immunoconjugates, vary widely. The BT062 trials in human
subjects showed not only tolerable toxicity against non-cancer
cells expressing CD138 at different stable disease doses,
especially at doses up to 160 mg/m.sup.2, but also fast plasma
clearance at dosages up to about 50 mg/m.sup.2 in a weekly
administration scheme.
The immunoconjugate described herein can be administered in
combination with cytotoxic agents. These combinations are also
referred to herein as anticancer combinations.
Selection of Drug Combination Partners
A set of guidelines for designing combination chemotherapy regimens
has been developed (Takimoto, 2006). Abiding to these guidelines
will generally increase the chances that a particular combination
realizes at least one of the three most important theoretical
advantages of combination chemotherapy over single-agent therapy:
1.) Maximize cell kill while minimizing host toxicities by using
agents with noninterfering dose-limiting toxicities; 2.) Increasing
the range of drug activity against tumor cells with endogenous
resistance to specific types of therapy; and 3.) Preventing or
slowing the development of newly resistant tumor cells.
Recommended principles to consider for selecting agents for use in
combination chemotherapy regimens comprise:
a) selecting drugs known to induce complete remission as single
agents,
b) selecting drugs with different mode of actions and with additive
or synergistic cytotoxic effects,
c) selecting drugs with different dose limiting toxicities,
d) selecting drugs with different patterns of resistance to
minimize cross resistance.
Also, drugs should be administered at their optimal dose and
schedule (e), and the administration should be performed at
consistent intervals, whereas the treatment free period should be
as short as possible to allow for recovery of the normal tissue (f)
(Takimoto et al, 2009).
Synergistic effects or just additive effects can be counteracted by
a variety of factors: For example, the components of an anticancer
combination might inactivate each other, e.g., by binding each
other. In addition, one component of an anticancer combination
might interfere with the mode of action of another component. For
example: Lenalidomide downregulates cell adhesion receptors such as
CD138, which is the target of the immunoconjugate of present
invention (Quach et al., 2010, Udi et al, 2010). The proteasome
inhibitor bortezomib causes G2/M cell cycle arrest (Wang et al.,
2009) which is also affected by anti-mitotic agents. Thus, if the
effector molecule of the immunoconjugate is a maytansinoid, it will
share a target for action with bortezomib, which is considered
disadvantageous.
Dosages, routes of administration and recommended usage of the
cytotoxic agents according of the present invention which have been
widely used in cancer therapy are known in the art and have been
described in such literature as the Physician's Desk Reference
(PDR). The PDR discloses dosages of the agents that have been used
in treatment of various cancers. The dosing regimen and dosages of
these cytotoxic agents that are effective will depend on the
particular cancer being treated, the extent of the disease and
other factors familiar to the physician of skill in the art and can
be determined by the physician. The 2006 edition of the Physician's
Desk Reference (PDR) discloses the mechanism of action and
preferred doses of treatment and dosing schedules for thalidomide
(p 979-983), VELCADE (p 2102-2106) and melphalan (p 976-979). One
of skill in the art can review the PDR, using one or more of the
following parameters, to determine dosing regimen and dosages of
the chemotherapeutic agents and conjugates that can be used in
accordance with the teachings of this invention. These parameters
include:
1. Comprehensive index according to a) Manufacturer b) Products (by
company's or trademarked drug name) c) Category index (for example,
"proteasome inhibitors", "DNA alkylating agents," "melphalan" etc.)
d) Generic/chemical index (non-trademark common drug names).
2. Color images of medications
3. Product information, consistent with FDA labeling including a)
Chemical information b) Function/action c) Indications &
Contraindications d) Trial research, side effects, warnings.
In the present context, one goal of employing combinations are a
reduction in the effective doses of the immunoconjugate of the
present invention, lowering their side effects and opening new
therapeutic windows with acceptable side effects. Another goal is
to reduce the effective dose of previously employed cytotoxic
agents such as VELCADE or lenalidomide and preferably reducing the
side effects of these agents. Similarly, the dosages Positive
consequences include, but are not limited to, prolongation of
treatment, higher dosages, other application schedules, better and
more sustained response to treatment.
Patients displaying a refractory phenotype towards drugs such as
lenalidomide, melphalan (study ongoing) might be rendered sensitive
again by the use of immunoconjugates according to the present
invention.
The term "cytotoxic agents" comprises "cytotoxic/cancer drugs"
including chemotherapeutic agents, in particular chemotherapeutic
agents that are generally used in rapidly dividing cells, namely:
Alkylating agents such as nitrogen mustards (e.g. melphalan,
cyclophosphamide, mechlorethamine, uramustine, chlorambucil,
ifosfamide) or nitrosureas (e.g. carmustine, lomustine,
streptozocin) or alkylsulfonates; Alkylating like agents such as
cisplatin, carboplatin, nedaplatin, oxaliplatin; or non classical
alkylating agents such as tetrazines, dacarbizine, procarbazine,
altretamine Anthracyclines such as doxorubicin and liposomal
doxorubicin (DOXIL) Alkaloids such as vincristine
The term "cytotoxic agents" also comprises immunomodulatory drugs
(ImiDs) such as thalidomide (or analogs), lenalidomide (CC-5013),
pomalidomide, actimid, which are used for myeloma therapy in view
of their pleitropic immunomodulatory properties. They commonly
display anti-inflammatory activity by inhibition of TNF alpha
production, but display also anti-angiogenic activity and
immunomodulatory properties such as T-cell co stimulation and
influence on regulatory T-cells (Quach et al., 2010).
The term "cytotoxic agent" also comprises steroids, such as, but
not limited to, dexamethasone and prednisone as well as proteasomal
inhibitors such as bortezomib (VELCADE) or carfilzomib which
induces the activation of programmed cell death in neoplastic cells
dependent upon suppression of pro-apoptotic pathways. Further
potent cytotoxic agents, include etoposide, which inhibits the
enzyme topoisomerse II, cytarabine, which, upon conversion damages
DNA when a cell cycle holds in the S phase (synthesis of DNA) and
thus in particular affects rapidly dividing cells such as cancer
cells. In addition, microtubule inhibitory agents such as vinca
alkaloids, taxanes (as described above in the context of effector
molecules) can also serve as cytotoxic agents according to the
present invention.
Also included in the definition are kinase inhibitors such as
sorafenib or HDAC (histone deacetylase), inhibitors such as
romidepsin as well as growth inhibitory agents, anti-hormonal
agents, anti-angiogenic agents, cardioprotectants,
immunostimulatory agents, immunosuppressive agents, angiogenesis
inhibitors and protein tyrosine kinase (PTK) inhibitors.
Further included in this definition are antibody based cytotoxic
agents including immunoconjugates and antibodies that have an art
recognized cytotoxic effect. Anti-CD40 is a preferred antibody.
Other antibodies include, but are not limited to, e.g., AVASTIN
(bevacizumab) or MYELOMACIDE (milatuzumab).
Thalomide (.alpha.-(N-phthalimido) glutarimide; thalidomide), is an
immunomodulatory agent. The empirical formula for thalidomide is
C.sub.13H.sub.10N.sub.2O.sub.4 and the gram molecular weight is
258.2. The CAS number of thalidomide is 50-35-1. It appears to have
multiple actions, including the ability to inhibit the growth and
survival of myeloma cells in various ways and to inhibit the growth
of new blood vessels.
Lenalidomide (REVLIMID) is a derivative of thalidomide representing
the second generation of immunomodulatory compounds (ImiDs) which
were initially developed as inhibitors of TNF alpha. Effects of
lenalidomide include growth arrest or apoptosis, abrogation of
myeloma cell adhesion to bone marrow stromal cells and modulation
of cytokines promoting cell growth, survival and drug resistance of
myeloma cells (Morgan et al., 2006). Lenalidomide is effective in
patients refractory to thalidomide. In addition to effects on
immune cells, ImiDs such as lenalidomide were suggested to cause
cell cycle arrest in G0/G1 phase. In addition, it is assumed that
ImiDs downregulate cell adhesion receptors (VLA-4, VLA-5, CD138)
(Quach et al., 2010; Udi et al, 2010). A downregulation of CD138
would be expected to cause a reduced binding of any CD138 targeting
agent, such as BT062, to target cells.
Proteasomal inhibitors can be divided into further subgroups: a)
naturally occurring peptide derivatives which have a C-terminal
epoxy ketone structure, beta-lactone derivatives, aclacinomycin A,
lactacystin, clastolactacystin; and b) synthetic inhibitors
(comprising modified peptide aldehyds, alpha, beta epoxyketon
structures, vinyl sulfones, boric acid residues, pinacolesters. A
preferred proteasomal inhibitor of the present invention is
bortezomib (PS 341; VELCADE, see discussion below). One of the
proposed mechanisms suggests that proteasomal inhibition may
prevent degradation of pro-apoptotic factors, permitting activation
of programmed cell death in neoplastic cells dependent upon
suppression of pro-apoptotic pathways. In addition, bortezomib
causes G2/M cell cycle arrest (Wang et al., 2009). Thus, bortezomib
might interfere with anti-mitotic agents which are part of the
immunoconjugate of the present invention, e.g., with the effect of
maytansinoid DM4, which acts also at this cell cycle phase.
Furthermore, PARP (Poly(ADP-ribose) Polymerase) cleavage, which
takes part in apoptosis, is also affected by both DM4 and
bortezomib. Accordingly, the combination of an immunoconjugate
comprising an anti-mitotic agent and a proteasomal inhibitor
displaying the features of bortezomib do not conform to the general
guidelines set forth previously to obtain synergistic effects
(Takimoto et al, 2009).
VELCADE (bortezomib) is a proteasome inhibitor used to treat
multiple myeloma. It is believed that VELCADE acts on myeloma cells
to cause cell death, and/or acts indirectly to inhibit myeloma cell
growth and survival by acting on the bone microenvironment. Without
being limited to a specific theory or mode of action, VELCADE thus
disrupts normal cellular processes, resulting in proteasome
inhibition that promotes apoptosis.
Dexamethasone is a synthetic glucocorticoid steroid hormone that
acts as an anti-inflammatory and immunosuppressant. When
administered to cancer patients, dexamethasone can counteract side
effects of cancer therapy. Dexamethasone can also be given alone or
together with other anticancer agents, including thalidomide,
lenalidomide, bortezomib, adriamycin or vincristine.
Substances for treatment, which may be used in combination with
BT062 also include immunomodulatory agents (e.g. thalidomide, and
lenalidomide, and pomalidomide), proteasome inhibitors (e.g.
bortezomib and carfilzomib), steroids (e.g. dexamethasone),
alkylating agents and high-dose chemotherapy, combinations (e.g.
Melphalan and Prednisone (MP), Vincristine, doxorubicin
(Adriamycin), and dexamethasone (VAD)), and bisphosphonates.
Currently, many combinations of in particular anti-myeloma drugs
are investigated in clinical trials. The purpose of the use of a
combination is generally either to enhance effectiveness, to
overcome a refractory phenotype, e.g., of myeloma cells, to reduce
side effects due to the use of lower concentrations of one of the
combination partners or a combination thereof. Using a low dose,
for example, of lenalidomide plus a low dose of dexamethasone was
shown to reduce toxicity (Rajkumar et al., 2010).
Especially in patients with relapsed or refractory multiple myeloma
several drug combination are and have been investigated.
A standard example for combined chemotherapeutics represents the
triple combination of vincristine, dexamethasone, doxorubicin (VAD
Regimen).
Proteasomal inhibitors such as bortezomib (VELCADE) have been
combined with myeloma drugs such as melphalan and prednisone (VMP).
This combination resulted in a complete response rate of 16% and an
overall response rate of 89% (Mateos et al., 2006).
Bortezomib has been also approved for use in combination with
liposomal doxorubicin for relapsed or refractory patients (Ning et
al., 2007).
Bortezomib is investigated in several clinical studies for use in
combination with dexamethasone, melphalan, prednisone and/or
thalidomide.
Bortezomib is also under investigation combined with liposomal
doxorubicin, cyclophosphamide and dexamethasone in multiple myeloma
patients. Combinations with vorinostat are currently under
investigation aiming at resensitizing patients to bortezomib which
are refractory to this drug.
Thalidomide, which is administered orally, has been combined with
melphalan/prednisone (MPT) (Facon et al., 2006) or dexamethasone or
bendamustine (Ponisch et al., 2008).
Moreover, lenalidomide (REVLIMID), an immunomodulatory drug, used
in combination with dexamethasone, resulted in a prolonged time to
tumor progression and increased survival compared to dexamethasone
alone (Weber et al., 2006). Lenalidomide combined with
dexamethasone has been also studied in newly diagnosed patients
(Rajkumar et al., 2005) as well as the combination with
melphalan/prednisone (RMP) (Palumbo et al., 2006).
US Patent Publication 2010/0028346 to Lutz et al., describes
synergistic effects of certain immunoconjugates with
chemotherapeutic agents.
The term "in combination with" is not limited to the administration
at exactly the same time. Instead, the term encompassed
administration of the immunoconjugate of the present invention and
the other regime (e.g. radiotherapy) or agent, in particular the
cytotoxic agents referred to above in a sequence and within a time
interval such that they may act together to provide a benefit
(e.g., increased activity, decreased side effects) that is
increased compared to treatment with only either the
immunoconjugate of the present invention or, e.g., the other agent
or agents. It is preferred that the immunoconjugate and the other
agent or agents act additively, and especially preferred that they
act synergistically. Such molecules are suitably provided in
amounts that are effective for the purpose intended. The skilled
medical practitioner can determine empirically, or by considering
the pharmacokinetics and modes of action of the agents, the
appropriate dose or doses of each therapeutic agent, as well as the
appropriate timings and methods of administration. As used in the
context of the present invention "co-administration" refers to
administration at the same time as the immunoconjugate, often in a
combined dosage form.
Synergistic effects that are effects of two components such as an
immunoconjugate and a cytotoxic agent that exceeds a strictly
additive effect. These synergistic effects might be counteracted by
a number of factors further discussed below.
Synergism has been calculated as follows (Yu et al., 2001;
Gunaratnam et al., 2009): RATIO(r)=expected
FTV(combination)/observed FTV(combination)
FTV: Fractional tumor volume=mean tumor volume (test)/mean tumor
volume (control)
A ratio>1 is regarded as synergistic, whereas r<1 is less
than additive.
The ratio (r) is, when above 1, also referred to herein as "SYNERGY
RATIO."
The ACTIVITY RATING is another measurement for the effects of a
combination. This rating is based on the Log.sub.10) cell kill
Log.sub.10 cell kill=(T-C)/T.sub.d.times.3.32 where (T--C) or tumor
growth delay, is the median time in days required for the treatment
group (T) and the control group (C) tumours, to reach a
predetermined size (600 mm.sup.3). T.sub.d is the tumor doubling
time, based on the median tumor volume in the control mice, and
3.32 is the number of cell doublings per log of cell growth
(Bissery et al., 1991). A Log.sub.10, cell kill of higher than 2.8
indicates that the combination is highly active, a log.sub.10 cell
kill of 2.0-2.8 indicates that the combination is very active, a
log.sub.10 cell kill of 1.3-1.9 indicates that the combination is
active, a log.sub.10 cell kill of 0.7-1.2 indicates that the
combination is moderately active and a log.sub.10 cell kill of less
than 0.7 indicates that the combination is inactive.
As the person skilled in the art will appreciate, the amino acid
sequence of the preferred engineered targeting antibody portion of
an immunoconjugate, nBT062, can be varied without loss of the
functionality of the antibody portion in targeting CD138. This is
in particular true when the heavy chain variable region CDR3
comprising amino acid residues 99 to 111 of SEQ ID NO: 1, and light
chain variable region CDR3 comprising amino acid residues 89 to 97
of SEQ ID NO: 2, respectively of the antigen binding region (ABR).
Advantageously, the heavy chain variable region CDR1 and CDR2
comprising amino acid residues 31 to 35 and 51 to 68 of SEQ ID NO:
1, and/or (b) light chain variable region CDR1 and CDR 2 comprising
amino acid residues 24 to 34 and 50 to 56 of SEQ ID NO: 2,
respectively of the antigen binding region (ABR) are also
maintained.
The term "sequence identity" refers to a measure of the identity of
nucleotide sequences or amino acid sequences. In general, the
sequences are aligned so that the highest order match is obtained.
"Identity", per se, has recognized meaning in the art and can be
calculated using published techniques. (See, e.g.: Computational
Molecular Biology, Lesk, A. M., ed., Oxford University Press, New
York, 1988; Biocomputing: Informatics and Genome Projects, Smith,
D. W., ed., Academic Press, New York, 1993; Computer Analysis of
Sequence Data, Part I, Griffin, A. M., and Griffin, H. G., eds.,
Humana Press, New Jersey, 1994; Sequence Analysis in Molecular
Biology, von Heinje, G., Academic Press, 1987; and Sequence
Analysis Primer, Gribskov, M. and Devereux, J., eds., M Stockton
Press, New York, 1991). While there exist a number of methods to
measure identity between two polynucleotide or polypeptide
sequences, the term "identity" is well known to skilled artisans
(Carillo, H. & Lipton, D., SIAM J Applied Math 48:1073
(1988)).
Whether any particular nucleic acid molecule is at least 50%, 60%,
70%, 75%, 80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% identical to,
for instance, the nBT062 nucleic acid sequence, or a part thereof,
can be determined conventionally using known computer programs such
as DNAsis software (Hitachi Software, San Bruno, Calif.) for
initial sequence alignment followed by ESEE version 3.0 DNA/protein
sequence software (cabot@trog.mbb.sfu.ca) for multiple sequence
alignments.
Whether the amino acid sequence is at least 50%, 60%, 70%, 75%,
80%, 85%, 90%, 95%, 96%, 97%, 98% or 99% identical to, for instance
SEQ ID NO:1 or SEQ ID NO:2, or a part thereof, can be determined
conventionally using known computer programs such the BESTFIT
program (Wisconsin Sequence Analysis Package, Version 8 for Unix,
Genetics Computer Group, University Research Park, 575 Science
Drive, Madison, Wis. 53711). BESTFIT uses the local homology
algorithm of Smith and Waterman, Advances in Applied Mathematics
2:482-489 (1981), to find the best segment of homology between two
sequences.
When using DNAsis, ESEE, BESTFIT or any other sequence alignment
program to determine whether a particular sequence is, for
instance, 95% identical to a reference sequence according to the
present invention, the parameters are set such that the percentage
of identity is calculated over the full length of the reference
nucleic acid or amino acid sequence and that gaps in homology of up
to 5% of the total number of nucleotides in the reference sequence
are allowed.
If, in the context of the present invention, reference is made to a
certain sequence identity with a combination of residues of a
particular sequence, this sequence identity relates to the sum of
all the residues specified.
As discussed above, BT062 is an immunoconjugate comprising the
CD138 targeting chimeric antibody nBT062 that is attached via a
linker, here SPDB, to the cytostatic maytansinoid derivative DM4. A
chemical representation of BT062 is provided in FIGS. 1 and 2.
Immunoconjugates comprising nBT062 and a maytansinoid effector
molecule are often characterized in terms of their linker and
maytansinoid effector, e.g., nBT062-SMCC-DM1, is an immunoconjugate
comprising nBT062, SMCC (a "noncleavable" linker containing a
thioester bond) and DM1 as an effector. More generically, an
immunoconjugate containing nBT062 and an effector molecule may also
be described as nBT062-linker-effector or just as nBT062-effector
(nBT062N, wherein N is any effector described herein (see also US
Patent Publication 20090232810).
In one example, BT062 binds to CD138-positive multiple myeloma
cells. Once the target cell internalizes and/or releases the
immunoconjugate, DM4 is released from the targeting molecule,
thereby restoring its original cytotoxic potency of DM4. Thus,
BT062 provides a targeted antibody payload (TAP), wherein the
functional attachment of DM4 to nBT062 keeps the cytotoxic drug
inactive until it reaches/is internalized into the CD138 expressing
target cell.
Data from nonclinical studies investigating cytotoxicity of BT062
in multiple myeloma cells and animal models discussed herein
demonstrate that BT062 has highly significant antimyeloma activity
at doses that are well tolerated in a murine model.
A phase I open-label, dose escalation, repeated single dose study
in patients with relapsed or relapsed/refractory multiple myeloma
has been conducted (US patent publication: 20110123554;
International publication: WO 2010 128087).
The immunoconjugates disclosed herein can be administered by any
route, including intravenously, parenterally, orally,
intramuscularly, intrathecally or as an aerosol. The mode of
delivery will depend on the desired effect. A skilled artisan will
readily know the best route of administration for a particular
treatment in accordance with the present invention. The appropriate
dosage will depend on the route of administration and the treatment
indicated, and can readily be determined by a skilled artisan in
view of current treatment protocols.
Pharmaceutical compositions containing the immunoconjugate of the
present invention and/or any further cytotoxic agent as active
ingredients can be prepared according to conventional
pharmaceutical compounding techniques. See, for example,
Remington's Pharmaceutical Sciences, 17th Ed. (1985, Mack
Publishing Co., Easton, Pa.). Typically, effective amounts of
active ingredients will be admixed with a pharmaceutically
acceptable carrier. The carrier may take a wide variety of forms
depending on the form of preparation desired for administration,
for example, intravenous, oral, parenteral, intrathecal,
transdermal, or by aerosol.
The anticancer combinations of the present invention can preferably
be either in the form of pharmaceutical compositions or in the form
of kits comprising the components of the anticancer combination in
different containers. The components of the kit are usually
administered in combination with each other, often they are
co-administered either in a combined dosage form or in separate
dosage forms. Such kits can also include, for example, other
components, a device for administering the components or
combination, a device for combining the components and/or
instructions how to use and administer the components.
For oral administration, the immunoconjugate and/or cytotoxic agent
can be formulated into solid or liquid preparations such as
capsules, pills, tablets, lozenges, melts, powders, suspensions or
emulsions. In preparing the compositions in oral dosage form, any
of the usual pharmaceutical media may be employed, such as, for
example, water, glycols, oils, alcohols, flavoring agents,
preservatives, coloring agents, suspending agents, and the like in
the case of oral liquid preparations (such as, for example,
suspensions, elixirs and solutions); or carriers such as starches,
sugars, diluents, granulating agents, lubricants, binders,
disintegrating agents and the like in the case of oral solid
preparations (such as, for example, powders, capsules and tablets).
Because of their ease in administration, tablets and capsules
represent the most advantageous oral dosage unit form, in which
case solid pharmaceutical carriers are obviously employed. If
desired, tablets may be sugar-coated or enteric-coated by standard
techniques. The active agent must be stable to passage through the
gastrointestinal tract. If necessary, suitable agents for stable
passage can be used, and may include phospholipids or lecithin
derivatives described in the literature, as well as liposomes,
microparticles (including microspheres and macrospheres).
For parenteral administration, the immunoconjugate and/or cytotoxic
agent may be dissolved in a pharmaceutical carrier and administered
as either a solution or a suspension. Illustrative of suitable
carriers are water, saline, phosphate buffer solution (PBS),
dextrose solutions, fructose solutions, ethanol, or oils of animal,
vegetative or synthetic origin. The carrier may also contain other
ingredients, for example, preservatives, suspending agents,
solubilizing agents, buffers and the like. When the unconjugated
targeting agent and/or immunoconjugate and/or cytotoxic agent are
being administered intracerebroventricularly or intrathecally, they
may also be dissolved in cerebrospinal fluid.
Dosages administered to a subject may be specified as amount, per
surface area of the subject (which includes humans as well as
non-human animals). The dose may be, in a (multiple) single dose
regimen, generally lasting 21 days, administered to such a subject
in amounts, preferably, but not exclusively from about 5 mg/m.sup.2
to about 300 mg/m.sup.2, including about 10 mg/m.sup.2, about 20
mg/m.sup.2, about 40 mg/m.sup.2, about 50 mg/m.sup.2, about 60
mg/m.sup.2, about 80 mg/m.sup.2, about 100 mg/m.sup.2, about 120
mg/m.sup.2, about 140 mg/m.sup.2, about 150 mg/m.sup.2, about 160
mg/m.sup.2 and about 200 mg/m.sup.2. In a (repeated) multiple dose
regimen, the aggregate dose may administered within one cycle,
generally lasting 21 days, to such a subject may preferably, but
not exclusively be from about 120 mg/m.sup.2 to about 840
mg/m.sup.2, including about 120 mg/m.sup.2, about 130 mg/m.sup.2,
about 140 mg/m.sup.2, about 150 mg/m.sup.2, about 180 mg/m.sup.2,
about 195 mg/m.sup.2, about 240 mg/m.sup.2, about 300 mg/m.sup.2,
about 360 mg/m.sup.2, about 420 mg/m.sup.2, about 450 mg/m.sup.2,
about 480 mg/m.sup.2, 600 mg/m.sup.2, 720 mg/m.sup.2 about 840
mg/m.sup.2. The aggregate dose is administered preferably in at
least three individual doses, wherein the dose administration can
be isochronously, e.g., once every week, preferably on days 1, 8,
15 or anisochronously within, e.g., the period of 21 days.
Individual dosages administered may be about 3.times.40 mg/m.sup.2,
about 3.times.50 mg/m.sup.2, about 3.times.60 mg/m.sup.2, about
3.times.65 mg/m.sup.2, about 3.times.80 mg/m.sup.2, about
3.times.100 mg/m.sup.2, about 3.times.120 mg/m.sup.2, about
3.times.140 mg/m.sup.2, about 3.times.150 mg/m.sup.2, about
3.times.160 mg/m.sup.2, 3.times.200 mg/m.sup.2, 3.times.240
mg/m.sup.2 about 3.times.280 mg/m.sup.2.
The immunoconjugates are suitably administered at one time or over
a series of treatments. In a multiple dose regime these amounts may
be administered once a day, once a week or once every two weeks.
Loading doses with a single high dose or, alternatively, lower
doses that are administered shortly after one another followed by
dosages timed at longer intervals constitute a preferred embodiment
of the present invention. E.g., in a multiple dose regimen, a
loading dose of anywhere between 100 to 160 mg/.sup.2 could be
combined with one or two subsequent doses of 40 to 100 mg/m.sup.2.
In a preferred embodiment, the timing of the dosages are adjusted
for a subject so that enough time has passed prior to a second
and/or any subsequent treatment so that the previous dose has been
metabolized substantially, but the amount of immunoconjugate
present in the subject's system still inhibits, delays and/or
prevents the growth of a tumor. An exemplary "repeated multiple
dose" regime comprises administering doses of immunoconjugate of
about 10, 20, 40, 50, 60, 65, 80, 100, 120, 140, 160, 180, 200, 220
or 240 mg/m.sup.2 once every week. Alternatively, a high initial
dose of, e.g., 160 mg/m.sup.2 may be followed by a one, two, or
tri-weekly maintenance dose of, e.g., about 20 mg/m.sup.2. Other
combinations can be readily ascertained by the person skilled in
the art. However, other dosage regimens may be useful. The progress
of this therapy is easily monitored by known techniques and assays.
Dosage may vary, amongst others, depending on whether they are
administered for preventive or therapeutic purposes, the course of
any previous therapy, the patient's clinical history, the patient's
disease status, the patient's tumor load, the patient's genetic
predisposition, the patient's concomitant diseases, the disease
stage upon first treatment and response to the targeting
agent/immunoconjugate, the side effects experienced by the patient
and the discretion of the attending physician.
When a dose X of an immunoconjugate is said to significantly exceed
another dose Y, it means that total (e.g., aggregate) dose X
exceeds total (e.g., single) dose Y by at least 10% (e.g., if dose
X is 100 mg/m.sup.2, a dose Y that significantly exceeds dose X is
at least 110 mg/m.sup.2), preferably about 20% more preferably
about 30%, 40%, 50%, 60% or even more.
The term individual dose is in particular when used in the context
of a multiple dose regime used to describe a defined dose
administered in a single administration and can be contrasted to
the aggregate dose administered, e.g., in an active treatment
cycle, which is the sum of the individual doses administered in
said treatment cycle. E.g., three individual doses in an active
treatment cycle lasting, e.g., 21 days of 100 mg/m.sup.2 result in
an aggregate dose of 300 mg/m.sup.2.
The level of an immunoconjugate in a patient's body fluid such a,
e.g., in the patient's plasma, serum or plasma is measured by
methods well known in the art. Plasma levels can be assessed via
different pharmacokinetic (PK) assay like the one described under
Materials and Methods. The levels of the immunoconjugate in the
serum or plasma or other blood derived body fluid is generally
determined 2 to 4 hours after the start of the respective
administration, respectively, wherein said administrations are
preferably in form of an infusion. This generally corresponds to
0-2 hours after completion of an administration, in particular an
infusion.
The present invention is, in one embodiment, directed to a
maintenance therapy. As can be seen in FIG. 28 long-term therapy
with up to 160 mg/m.sup.2 once every 21 days is successfully
achieving stable disease or even minor response, but at least
progression free survival. The Figure also shows that plasma
concentrations of BT062 increased over time indicating a decrease
of tumor burden under treatment. This type of therapy is well
suited to follow a repeated multiple dose regimen of, e.g., weekly
administration. A typical maintenance therapy with dosing up to 160
mg/m.sup.2 once every three weeks may follow a repeated multiple
dose regimen (e.g. once every week for three weeks). Depending on
the tumor burden, lowering the doses may be employed, whereby,
e.g., plasma levels of the immunoconjugate or other relevant
parameters may serve to determine the appropriate dosing for
maintenance therapy. Maintenance can be achieved by threshold
levels of the immunoconjugate, which are permanently
present/maintained in the subject, so that there is a constant
amount of immunoconjugate available. In a preferred embodiment, a
tumor in a subject/the target cells are permanently exposed to
immunoconjugate, so that no new tumor cells can grow, or that they
are quickly destroyed due to a constant presence of the
immunoconjugate in the subject, which is reflected by a certain
measurable level of immunoconjugate in the subject's, e.g.,
plasma.
The maintenance therapy preferably reduces administration
frequency. However, other maintenance therapies resulting in
particular in, e.g., reduced aggregate doses of immunoconjugate
administered are also preferred. The particular design of a
maintenance therapy will depend, among others, on tumor burden. The
level immunoconjugate and/or other efficacy blood parameters such
as M-protein, FLC or a tumor/cancer specific marker can be
determined in a body fluid, such as the plasma, serum or urine of
the subject (patient) and the maintenance dose and frequency of the
dose can be made dependent on the level or a change in the level of
the efficacy blood parameter. A kit that may be employed in this as
well as other contexts of the present invention may include
markers, in particular antibodies, preferably labeled antibodies,
against the immunoconjugate, e.g., against the toxin portion of the
immunoconjugate, which can be used to quantify the immunoconjugate
in a body fluid of a subject. A signal obtained from the binding of
the, e.g. labeled antibody, can be correlated to the amount of
immunoconjugate present in the body fluid of a subject. Suitable
individual dose levels, both for repeated multiple doses as well as
repeated single doses, for maintenance therapy are, e.g., 60-160
mg/m.sup.2.
Extended treatment free periods may be beneficial for the patient.
Surprisingly, it was found that after even an extended resting
period (see days 400 to 421) stable disease could still be
maintained (see FIG. 28).
The present invention is, in one embodiment, directed to an
administration regimen, preferably with rapid plasma clearance. The
regimen provides generally less than about 280 mg/m.sup.2, less
than 120 mg/m.sup.2, less than 100 mg/m.sup.2, less than 80
mg/m.sup.2, including no more than about 40 mg/m.sup.2, more
preferably no more than about 20 mg/m.sup.2, even more preferably
no more than about 10 mg/m.sup.2 in a given week for at least three
consecutive weeks which define an interval (cycle). The 10
mg/m.sup.2 to 280 mg/m.sup.2 range translates to an average daily
dose of about 1.43 mg/m.sup.2 to 40 mg/m.sup.2 Thus, average daily
doses of about 0.4 mg/m.sup.2 to about 17.14 mg/m.sup.2, including
about 5.7 mg/m.sup.2, about 7.1 mg/m.sup.2, 8.58 mg/m.sup.2, 9.28
mg/m.sup.2, 11.4 mg/m.sup.2, 14.28 mg/m.sup.2, 17.1 mg/m.sup.2,
22.85 mg/m.sup.2, 25.7 mg/m.sup.2 (180 mg/m.sup.2), 28.58
mg/m.sup.2 34.2 mg/m.sup.2, 40 mg/m.sup.2 are part of the present
invention. Low dose administration schemes up to 100 mg/m.sup.2 are
associated with rapid plasma clearance at the in early elimination
phase, that is, any time during administration up to two hours
after administration is completed. What distinguishes the low dose
administration regime from other low dose regimens is the rapid
plasma clearance, which is defined by a measured Cmax during that
period that is preferably less than 55%, less than 50%, less than
40%, or less than 35% of the theoretical Cmax (Tables 11).
Administration regimens are, at higher levels, accompanied by less
rapid plasma clearance, that is by plasma clearances that exceed
55%, often 60%, 70% 80% or 90% of the theoretical Cmax value, which
are referred to herein as moderate (equal or >55%, but <80%
of the theoretical Cmax value) or slow plasma clearance (equal or
>80% of the theoretical Cmax value). At these clearances it was
surprisingly found that, despite the relative high concentration of
immunoconjugate in the plasma, these administration regimens still
did not result in DLTs. This is despite the fact that expression
levels of CD138 on non target cells that express CD138, e.g., cells
of vital organs, such as the epithelium which are not target of any
treatment, are also relative high in CD138 (immunohistochemistry
analyses with the CD138 antibody BB4 showed that the reactivity to
this antibody to the epithelium matched that of MM patient plasma
cells (US Patent Publication 20070183971)). Expression levels of
CD138 on target and non target cells that produce equal scores
(e.g. plus three ((+++) as in the above example) in
immunohistochemistry analyses are referred to herein as comparable
expression levels and are part of the present invention. In an
alternative embodiment, the expression levels on target cells were
actually consistently below that of the epithelium (e.g., plus one
(+) or plus two (++) vs. plus three (+++) for the epithelium). Some
tumor target cells show mixed expression levels, such as, that some
cells have an expression level of plus two and some an expression
level of plus three. The mean of a representative number of cells
(such as 100 randomly sampled cells) will determine whether these
tumor target cells in question fall under the definition of having
expression levels comparable or below that of the epithelium. These
treatment regimens are generally above 40 mg/m.sup.2, but below 180
or even 280 mg/m.sup.2 given weekly at least for three consecutive
weeks which define an active treatment cycle, which translates to a
daily doses of about 5.71 mg/m.sup.2 to about 25.71 mg/m.sup.2
(180), 40 mg/m.sup.2 (280).
With respect to Patient 8 (see FIG. 18 for numbering) it was
noticeable, that this patient had, during the entire treatment of
168 days, while there was an increase in FLC until day 141, no
disease progression (see also FIG. 21), reflecting the efficacy of
BT062 administration, while Patient 6 showed no disease progression
for 6 cycles (FIG. 20).
FIG. 19B clearly demonstrates that a constant amount of approx. 20
.mu.g/ml is lost, presumable during infusion. This has been
calculated from the difference between the plasma levels (defined
here as Cmax) determined in the samples and the theoretically
achievable Cmax value. In Table 11c the absolute values for the
plasma level determined between 0 and 2 hours after the end of
infusion are displayed and compared to the theoretically achievable
Cmax plasma values ("Theoretical Cmax" as calculated by the formula
below)
Theoretical Cmax was Calculated According to the Following Assumed
Parameters:
TABLE-US-00009 Patient's Body Surface Area 1.9 m.sup.2 Patient's
Weight 70 Kg Patient's Plasma Volume 40 ml/kg
.times..times..times..times..times..times..times..times..times.
##EQU00001##
In certain embodiments, the invention is also directed to a
treatment regimen, wherein the dose can be adapted according to the
measured level of an efficacy blood parameter found in a body fluid
such as plasma. This allows for a patient tailored treatment. For
example, the dose of BT062 may be adapted according to plasma
levels determined between 0 and 4 hours after completion of an
administration, such as an infusion.
As can be seen in FIG. 29, the parameter M-protein (decrease in its
level) indicated in this patient disease improvement. At the same
time plasma levels (Cmax values) of BT062 increased. With
increasing treatment cycles, the tumor load was reduced and
concomitantly, plasma levels ("Cmax values") determined in the
plasma after 0-4 hours after completition of the infusion with
BT062 increased, so that a negative correlation between the
M-protein level and the Cmax were observed. The increase in Cmax
values can be explained by a decrease in tumor volume, which means
that fewer tumor cells are present, which is reflected in the
decrease in M-Protein level. Less CD138 as a target source would
lead to less binding sites for BT062. As a consequence, more BT062
can be detected in the plasma. Thus, the Cmax values can be used to
evaluate the response to treatment (increase in Cmax correlates
with efficacy). If, in a given instance, the Cmax values increases,
when compared to Cmax of a prior injection (or any injection, where
no efficacy was seen) e.g. by 10%, 20% or more, this indicates that
fewer binding sites on the tumor are present and that thus tumor
size decrease. In this example, the dose can be adjusted to a lower
dose in the next treatment cycle. As a result, a lower amount of
drug needed and toxicities can be prevented.
A repeated single dose refers to a sequence of administrations,
wherein the administration following an administration is regarded
to be independent of this preceding administration. Thus, in the
present context, the level of immunoconjugate in a subject's blood
can be regarded as equal after each administration. Each time the
immunoconjugate is administered, it is expected that equal levels
of immunoconjugate are initially present in the blood.
Administration intervals between the "single doses" of the repeated
single doses are defined according to the theoretically calculated
half life of an isotype of an immunoconjugate, in the case of
BT062, IgG4.
In general, the half life of therapeutic antibodies depends mainly
on the antibody characteristics/its structural features (e.g.
binding to Fc receptors) and the target. For example, the binding
affinity of the Fc part to the neonatal receptor FcRn is affecting
the half life. By binding to FcRn in endosomes, the antibody is
salvaged from lysosomal degradation and recycled to the
circulation, which prolongs the half life. For an IgG4 a half life
of 15.6 (+/-4.5) days (Alyanakian et al., 2003; Salfeld et al.,
2007) has been reported. In the study referenced herein, a
"repeated single dose" has been chosen that has administration
intervals of three weeks. However, about three weeks, about four
weeks, but also about five or about six weeks are alternative
intervals for repeated single doses. A reference to "about" refers
in the context of three weeks to +/-96 hours and in the context of
four to six weeks to +/-120 hours.
A multiple dose regimen or a multiple dose refers to a sequence of
administrations, wherein the administration following an
administration is regarded to be dependent of the preceding
administration. Thus, in the present context, the level of
immunoconjugate in a subject's blood is expected in a second and
subsequent administration to be above the base level that existed
prior to the initial administration. At each administration
following the initial administration of the immunoconjugate, a
certain level of immunoconjugate is expected to be present in the
blood. Administration intervals between the individual "doses" of
the multiple doses are defined, as in the context of the repeated
single doses, according to the theoretically calculated half life
of an isotype of an immunoconjugate, in the case of BT062, IgG4.
For an IgG4 a half life of 15.6 (+/-4.5) days (Alyanakian et al.,
2003; Salfeld et al., 2007) has been reported. In the study
referenced herein, a "multiple dose" has been chosen that has
administration intervals of one week. However, even shorter
administration intervals may be chosen such as 4 days or even 3
days. Alternatively, a longer interval can be chosen. However, at a
minimum a multiple dose implies at least 2 administrations in a 21
day period. A reference to "about" refers in the context of one
week to +/-32 hours, in the context of 4 days, +/-18 hours and in
the context of 3 days +/-12 hours. A repeated multiple dose refers
to multiple doses administered in subsequent treatment cycles,
which may include intermittent resting period(s) or treatment free
period(s), including extended resting period(s) or treatment free
period(s), that do not obliterate in whole the effects of the
previously administered multiple dose(s).
The actual level of immunoconjugate after the first and each
subsequent administration, however, depends on the de facto
"clearance" of the immunoconjugate from the, e.g., the plasma
("plasma clearance") immediately during/after completion of the
administration, in particular, 0-2 hours after completion of
administration. At 40 mg/m.sup.2 median infusion time was 40 min
within a range of 32 min to 1 hour 30 min. At the dose level of 120
mg/m.sup.2 median infusion time was 2 hours 2 min within a range of
1 hour 40 min to 2 hour 30 min. Accordingly, in an IV
administration, about 1 mg/m.sup.2 may, in certain embodiments, be
administered on average per minute, but administration times, of
about 1 mg/m.sup.2 per 30 seconds to about 1 mg/m.sup.2 per 120
seconds are well within range. Surprisingly, it was found that
BT062 cleared from the plasma considerably faster than either the
theoretical expected values or the values encountered with similar
immunoconjugates. This observation allowed for the design of new
administration regimens for the immunoconjugate both alone in a
monotherapy as well as in combination with other relevant agents,
in particular cytotoxic agents to provide effective anticancer
combinations.
Aggregate effective amount is the effective amount of
immunoconjugate administered within a period of a dosing regimen,
preferably in equal doses, e.g., once a week, for e.g. three weeks
such as on days 1, 8, and 15 of a 21 day dosing regimen or on days
1, 8, 15 of a 28 day dosing regimen wherein no dose is administered
on day 22.
The progress of the therapy is easily monitored by known techniques
and assays. Dosage may vary, amongst others, depending on whether
they are administered for preventative or therapeutic purposes, the
course of any previous therapy, the patient's clinical history, the
patient's disease status, the patient's tumor load, the patient's
genetic predisposition, the patient's concomitant diseases, the
disease stage upon first treatment and response to the targeting
agent/immunoconjugate, the side effects experienced by the patient
and the discretion of the attending physician.
The advantages of a low dose regime are wide-ranging. However, the
probably most significant advantage is minimizing the risk of
adverse side effects. While immunoconjugates generally permit
sensitive discrimination between target and normal cells, resulting
in fewer toxic side effects than most conventional chemotherapeutic
drugs, many immunoconjugates are still not completely free of side
effects. Despite superior targeting, the antigen of interest is
generally also expressed on non-cancer cells whose destruction
during therapy can lead to adverse side effects. In the case of
CD138, the antigen is in particular expressed on epithelial cells.
Also, the immunoconjugate might undergo processing within the body
that is unrelated to the procession in or at a target cell and a
certain percentage of effector molecules might be released at
locations remote from the target cells leading to toxic side
effects.
It was shown that the immunoconjugate of the present invention was
effective at low doses, while displaying clinically acceptable
toxicities (dosages up to 160 mg/m.sup.2 provided once every three
weeks). At doses up to at least 120 mg/m.sup.2 but in any event at
doses of less than 160 mg/m.sup.2 provided once every three weeks
(e.g., on day 1), the tested immunoconjugate also showed rapid
plasma clearance in human subjects. Tables 9 and 10 show the
clearance observed in repeated single dose regimens.
TABLE-US-00010 TABLE 9 Plasma concentrations after end of infusion
and effective Cmax mean values of BT062 from plasma obtained in
patients having received a single dose/repeated single dose BT062
(first and fourth cycle). Repeated dose administration in cycles of
21 days. Cmax values were obtained between 0 and 2 hours post
infusion. Administration cycles: cycle 1: day 1, cycle 2: day 22;
cycle 3: day 43; cycle 4: day 64 etc. plasma level of BT062
(.mu.g/ml) human effective Cmax effective Cmax dosage BT062 (cycle
1) mean (cycle 4) mean (mg/m.sup.2) theoretical Cmax (lowest;
highest) (lowest; highest) 10 7 1.11 n.a. 20 14 2.9 7.06 (1.66;
4.44) (6.79; 7.34) 40 27 4.31 2.51 (0.97; 9.86) (1.02; 3.68) 80 54
18.8 14.2 (13.4; 23.6) (7.4; 21) 120 81 21.4 n.a. (15.1; 28.7) 160
109 81.2 77.4 (73.7; 85.5) 200 136 82.0 n.a. (68.0; 102.4) n.a.
data not available
TABLE-US-00011 TABLE 10 Effective Cmax mean values of BT062 from
plasma obtained in patients having received a single dose/repeated
single dose BT062 (first and fourth cycle). Repeated dose
administration in cycles of 21 days. Maximum values were obtained
within the first 2 hours post injection. Cmax values were obtained
between 0 and 2 hours post infusion. Effective Cmax is indicated in
percentage of theoretically calculated Cmax. Administration cycles:
cycle 1: day 1, cycle 2: day 22; cycle 3: day 43; cycle 4: day 64
etc. plasma level of BT062 (.mu.g/ml) human percentage percentage
Dosage effective of effective of BT062 theoretical Cmax theoretical
Cmax theoretical (mg/m.sup.2) Cmax (cycle 1) Cmax (n) (cycle 4)
Cmax (n) 10 7 1.1 15% (3) n.a. n.a. 20 14 2.9 20% (4) 7.06 49% (2)
40 27 4.31 16% (3) 2.51 9% (3) 80 54 18.8 34% (3) 14.2 26% (2) 120
81 21.4 26.5% (3) n.a. n.a. 160 109 81.2 74.5% (4) 77.4 71% (1) 200
136 82.0 60% (3) n.a. n.a n.a. data not available n: number of
patients
The theoretical Cmax was calculates as described above.
Although the half life of BT062 in plasma of human subjects treated
proved to be significantly lower than the plasma half life observed
in cynomolgus monkeys (days) and in human plasma ex vivo (14 days),
the immunoconjugate still showed efficacy in human subjects, even
at administrations as low as 20 mg/m.sup.2 suggesting an
accelerated tumor targeting and tumor cell binding which results in
an increased efficacy.
The accelerated tumor targeting could be confirmed by measurements
of the receptor (CD138) occupancy on multiple myeloma cells in the
bone marrow of a multiple myeloma patients. As can be seen in Table
11e at different repeated multiple doses regimen, the receptor
occupancy at the tumor site in the bone marrow came close to 100%
within four hours after the end of the administration of the
immunoconjugate, supporting an antibody mediated accelerated tumor
targeting. Accordingly, the present invention is directed at
immunoconjugates having an early, that is 0-12, 0-10, 0-8, 0-6 or
0-4 hours after completion of administration, target tissue
receptor (CD138) occupancy of between 70-100%, preferably 80-100%,
more preferably 90-100%, even more preferably more than 94, 95, 96,
97 or 98% "receptor occupancy" (RO). The "receptor" is hereby CD138
and the RO is measured according to the following formula: RO=(MFI
Sample 1-MFI Sample 3)/(MFI Sample 2-MFI Sample 3)
MFI=Mean Fluorescence Intensity measured via flow cytometry
Samples of myeloma cells in bone marrow aspirates.
Sample 1: Bound immunoconjugate, here, BT062 was stained with
anti-May (May=matansinoid) antibodies.
Sample 2: Total CD138 was measured with anti-May antibodies after
receptor saturation with the immunoconjugate.
Sample 3: unspecific binding measure by incubation with an IgG1
isotope antibody.
As noted above, unusual rapid clearance from plasma of treated MM
patients was observed in the early elimination phase (observed
already during infusion and about 0 to 2 hours post infusion, ergo
completition of infusion) followed by generally normal terminal
elimination phase at dose levels up to 120 mg/m.sup.2, whereas a
more typical clearance profile was observed for all 4 patients at
the 160 mg/m.sup.2 and 200 mg/m.sup.2 dose (3 patients), even
though the clearance was still below the theoretical Cmax value. In
addition, in the administration regimens that showed rapid plasma
clearance at the early elimination phase, e.g. 20, 40, 80 and 120
mg/m.sup.2) not only rapid plasma clearance at the early
elimination phase was observed, but a response (decrease of urine
M-protein) was observed, including responses that manifested
themselves in a decrease of urine M-protein by more than 50% after
repeated single dosages (results not shown).
As discussed above, data supports that the rapid clearance from
plasma of treated MM patients observed in the early elimination
phase can be correlated to a high receptor occupancy at the target
cells.
Surprisingly it was found that in a multiple dose regimen rapid
plasma clearance occurred at aggregate dosages that were well above
the 120 mg/m.sup.2 and in fact close to the determined DLT of 160
mg/m.sup.2 for a repeated single dose regime, which opened up the
possibility for potent mono- or combination therapies due to low
the toxicities of the immunoconjugate in the multiple dose
regime.
Table 11a shows the % of theoretical Cmax values following
differently dosed weekly administration schemes lasting for 3 weeks
(21 days), ergo multiple dose regimens. The percent of theoretical
Cmax in the 65 mg/m.sup.2 cohort is higher than in the lower dosed
cohorts shown:
TABLE-US-00012 TABLE 11a 40 50 65 80 100 120 mg/m.sup.2 mg/m.sup.2
mg/m.sup.2 mg/m.sup.2 mg/m.sup.2 mg/m.sup.2 C1, D 1 29% 24% 43% 42%
61% 69% C1, D 8 39% 29% 63% 42% 81% 74% C1, D 15 43% 31% 72% 44%
89% 79% C2, D 1 33% 26% 52% 45% 94% 62% C2, D 8 37% 40% 61% 50%
102% 67% C2, D 15 41% 35% 52% 43% 111% 67% C3, D 1 28% 30% 52% 39%
109% C3, D 8 30% 29% 71% 53% 121% C3, D 15 26% 35% 73% 41% 142% C4,
D 1 24% 24% 125% C4, D 8 30% 45% 123% C4, D 15 35% 42% 135% Mean
(%) 33% 33% 60% 44% 108% 69% Standard 6% 7% 11% 4% 24% 6% deviation
% of theoretical Cmax: CX refers to the number of cycle: C1 is
cycle 1, wherein each cycle is 21 days long followed by one
treatment free week (or each cycle is considered 28 days long with
no administration on day 22). DX is the day within the cycle at
which the immunoconjugate is administered; D 8 is day 8 of the
cycle. The % theoretical Cmax was calculated as set forth above.
The high standard deviation for 100 mg/m.sup.2 and the relative
lower percentiles of Cmax at 120 mg/m.sup.2 indicate that the high
percentiles at 100 mg/m.sup.2 are a deviation.
TABLE-US-00013 TABLE 11b Conc. Missing to theor. Cmax [mg/m.sup.2]
40 50 65 80 100 120 mg/m.sup.2 mg/m.sup.2 mg/m.sup.2 mg/m.sup.2
mg/m.sup.2 mg/m.sup.2 C1, D 1 19.3 25.7 24.9 31.5 26.5 25.4 C1, D 8
16.4 24.2 16.3 31.4 13.0 21.6 C1, D 15 15.5 23.5 12.2 30.5 7.2 17.5
C2, D 1 18.2 24.9 21.2 29.7 4.3 31.2 C2, D 8 16.9 20.3 17.3 27.0
-1.5 26.6 C2, D 15 16.0 21.9 21.2 31.0 -7.7 26.8 C3, D 1 19.4 23.8
21.3 33.0 -6.0 C3, D 8 19.1 24.2 12.8 25.8 -14.4 C3, D 15 19.9 21.9
11.7 32.1 -28.4 C4, D 1 20.6 25.8 -17.1 C4, D 8 19.0 18.8 -15.8 C4,
D 15 17.7 19.7 -24.1 Mean 18.6 23.0 17.7 29.9 6.8 SD 1.5 2.4 4.7
1.0 13.2
TABLE-US-00014 TABLE 11c Mean conc. missing to theor. Cmax per
Cycle 40 50 65 80 100 120 mg/m.sup.2 mg/m.sup.2 mg/m.sup.2
mg/m.sup.2 mg/m.sup.2 mg/m.sup.2 C1, D 1 17.1 24.5 17.8 31.1 15.6
21.5 C1, D 8 C1, D 15 C2, D 1 17.0 22.4 19.9 29.2 -1.7 28.2 C2, D 8
C2, D 15 C3, D 1 19.5 23.3 15.3 30.3 -16.3 C3, D 8 C3, D 15 C4, D 1
19.1 21.4 -19.0 C4, D 8 C4, D 15
Table 11b and 11c: CX refers to the number of cycle. C1 is cycle 1,
wherein each cycle is 21 days long followed by one treatment free
week (or each cycle is considered 28 days long with no
administration on day 22). DX is the day within the cycle at which
the immunoconjugate is administered; D8 is day 8 of the cycle.
Shown in 11b are the concentrations (mg/m.sup.2) in absolute terms
that, based on the actual Cmax, are missing at each dosage level to
reach the theoretical Cmax. In 11c the actual numbers per
administration are shown, on the right side the mean concentrations
in each cycle are shown. It is also noticeable that the mean
concentration (11c) within one cycle and over the three cycles
shown is comparable and constant. Apart from a deviation at 100
mg/m.sup.2, the missing concentration also remains relatively
constant.
TABLE-US-00015 Plasma Dose level/Mean SD (mg/m.sup.2) Time (days)
Patient (.mu.g/ml) (.mu.g/ml) 40 Pre-dose 4 0 0 40 0 (day of
administration), 2 4 7.78 2.23 (hr after completion of
administration) 40 before next dose 4 0.69 0.33 40 7.2 4 10.67 4.93
40 before next dose 4 0.63 0.55 40 14.2 4 11.61 5.50 40 before next
dose 4 0.70 0.62 50 Predose 3 0 0 50 0.2 3 8.20 0.90 50 before next
dose 3 0.45 0.46 50 7.2 3 9.70 3.58 50 before next dose 3 0.49 0.45
50 14.2 3 10.43 3.47 50 before next dose 2 0.38 0.53 65 Predose 4 0
0 65 0.2 4 19.18 8.43 65 before next dose 4 1.41 0.66 65 7.2 4
27.83 8.95 65 before next dose 4 1.63 0.66 65 14.2 4 31.94 18.12 65
before next dose 4 1.77 0.93 80 Predose 3 0 0 80 0.2 3 22.81 3.20
80 before next dose 3 1.30 0.53 80 7.2 3 22.91 6.37 80 before next
dose 3 1.27 0.68 80 14.2 3 23.81 6.46 80 before next dose 3 1.41
0.70 100 Predose 4 0 0 100 0.2 4 41.40 23.02 100 before next dose 3
3.77 0.78 100 7.2 3 54.85 24.34 100 before next dose 3 4.13 1.82
100 14.2 3 60.70 29.81 100 before next dose 3 6.04 2.63 120 Predose
2 0 0 120 0.2 2 56.00 32.46 120 before next dose 2 2.35 2.74 120
7.2 2 59.85 30.96 120 before next dose 2 2.50 6.68 120 14.2 2 63.90
28.82 120 before next dose 2 3.05 10.42
Table 11d represents the mean values of plasma level (.mu.g/ml) of
immunoconjugate at dose levels between 40 and 120 mg/m.sup.2 before
and after the weekly administration. The mean plasma level before
the next administration ("before next dose") starts to increase
slightly. At 65 and 80 mg/m.sup.2, plasma levels before the next
dose stay above 1 .mu.g/ml. At 100 and 120 mg/m.sup.2, the level
before the next administration is between approx. 2 and 4 .mu.g/ml,
thus the plasma levels of subsequent treatments, are somewhat
higher than those in the first cycle, indicating some accumulation
prior to the next injection.
TABLE-US-00016 TABLE 12 Receptor Occupancy (RO) in Repeated
Multiple Dose Regimen: Bone marrow receptor occupancy was measured
via flow cytometry. Myeloma cells in bone marrow aspirates were
characterized by CD138 and CD38 staining (not shown). Bound BT062
was stained with anti-May antibodies (Sample 1). Total CD138 was
measured with anti-May antibodies after receptor saturation with
BT062 (Sample 2). Incubation with an IgG1 isotype antibody
determined unspecific binding to the sample (Sample 3). The
occupancy of CD138 was calculated with the following equation. RO =
(MFI Sample 1 - MFI Sample 3)/(MFI Sample 2 - MFI Sample 3) Weekly
Dose Level No. Cycles at Receptor occupancy Patient ID (mg/m.sup.2)
Term. (RO) 12 80 C8D15* 99% 12 80 C13D15** 37% 12 80 C14D15** 51%
22 140 C1D1* 86% 23 140 C1D1* Background to high 26 140 C1D1* 95%
28 140 C1D8** 58% 24 140 C1D1* 94% 25 140 C1D1* 98% 30 160 C1D1*
98% 31 160 C1D1* 76% wherein, MFI = Mean Fluorescence Intensity
Each cycle lasted 28 days with administration of the indicated dose
on days 1, 8 and 15. C13D15, for example, indicates the dose
administered on day 15 in the 13.sup.th cycle. In three of the
above, measurements are based on samples that were taken just prior
(within 12 hours) to the next administration and are marked with
double asterisks (**) and thus more than 6 days after the last
administration. The remainder of the measurements were taken
directly after an administration of BT062, here within 4 or 12 or
24 hours after completion of administration (*). As can be seen,
the RO was relatively low just prior to the next administration,
while the RO was high right after administration.
FIG. 13 illustrates the rapid plasma clearance for single dose
administrations ranging from 40 mg/m.sup.2 to 120 mg/m.sup.2, while
higher doses as illustrated here by a dose of 160 mg/m.sup.2,
showed plasma clearance closer to the theoretical value. FIG. 17
clarifies that the rapid plasma clearance cannot be attributed to a
buffering effect caused by soluble CD138. FIG. 14 shows how the
measured Cmax values of BT062 compared to the theoretical Cmax
values.
FIGS. 19A and 19A as well as Table 11a illustrate the rapid plasma
clearance in an administration scheme involving multiple doses. As
can be seen in a scheme that involves individual doses that are
administered on days 1, 8, and 15 and that add up within a cycle
(e.g., 21 days) to nearly a dosage that corresponds to DLTs of a
repeated single dose (3.times.50 mg/m.sup.2=150 mg/m.sup.2', vs.
160 mg/m.sup.2) of the immunoconjugate, the actual Cmax values
remain well beneath 50% of the theoretical Cmax value, while at the
DLT levels in a repeated single dose, the actual Cmax values are
well over 50% of the theoretical Cmax value.
Table 11b shows that at concentrations at which the actual Cmax is
on average already well above 50% of the theoretical Cmax, the
concentration missing to the theoretical Cmax, remains on average
similar, in the examples provided, namely around 20 .mu.g/ml (see
also FIG. 19B). This may point towards a "sink", which "ab/adsorps"
a certain portion of the immunoconjugate quickly, but becomes less
noticeable as doses increase. In fact at 100 mg/m.sup.2 this effect
appears only to occur during the first individual dose. However, it
rebounded at 120 mg/m.sup.2 making it likely that that 100
mg/m.sup.2 are a deviation. However, the sink of 20 .mu.g/ml is
observed here also at higher cycles.
Accordingly, the invention is also directed to a method of
pretreatment with an targeting agent, preferably an unconjugated
antibody, that is fed into this sink instead of the
immunoconjugate, which contain effector molecules, which are not
only toxic, but generally also costly. As the person skilled in the
art will understand, the sink may include tumor target cells as
well as CD138 expressing cells of other tissues. Thus, in one
aspect of the invention, the constant amount of +/-20 .mu.g/ml of
immunoconjugate which is consistently missing to reach the
theoretically Cmax value (FIG. 19B) promptly after or during
infusion, ergo is considered quickly to be ad-/absorbed by/bind to
said sink (also referred to herein as "antigen sink"). Such a sink
is filled in such an embodiment not by the immunoconjugate, but by
another agent, preferably an agent that binds to CD138. In this
embodiment, rather than having the immunoconjugate be ad-/absorbed
during/after administration, an alternative ad-/absorbent, e.g.,
unconjugated antibody, is administered. Assuming that the
immunoconjugate is lost in the sink, and thus potentially does not
contribute to the therapeutic effect, a pretreatment can be used to
a) minimize the toxicities which might be related to that "sink"
and b) lower the required amount of immunoconjugate to obtain
equivalent results.
This pretreatment may consist of administration of 20 .mu.g/ml
(+/-) of an unconjugated anti-CD138 antibody or fragment thereof,
preferably nBT062 and may fill this sink.
At repeated single doses of 160 mg/m.sup.2 which constitute a low
dose compared to administration schemes of other immunoconjugates,
terminal clearance profiles were closer to normal, that is, closer
to the theoretical Cmax values. However, a rapid reduction of FLC
in the serum could be observed after just a single administration,
which manifested itself in a partial response after the 2.sup.nd,
3.sup.rd and 4.sup.th administration (FIG. 26).
Analogues and Derivatives
One skilled in the art of therapeutic agents, such as cytotoxic
agents, will readily understand that each of such agents described
herein can be modified in such a manner that the resulting compound
still retains the specificity and/or activity of the starting
compound. The skilled artisan will also understand that many of
these compounds can be used in place of the therapeutic agents
described herein. Thus, the therapeutic agents of the present
invention include analogues and derivatives of the compounds
described herein.
For illustrative purposes of the uses of the immunoconjugates some
non-limiting applications will now be given and are
illustrated.
Materials and Methods
Chimeric Antibody Construction (cB-B4: nBT062)
B-B4
Murine antibody B-B4 as previously characterized (Wijdenes et al.,
Br J. Haematol., 94 (1996), 318) was used in these experiments.
Cloning and Expression of B-B4 and cB-B4/nBT062
Standard recombinant DNA techniques were performed as described in
detail in text books, for example in J. Sambrook; Molecular
Cloning, A Laboratory Manual; 2nd Ed. (1989), Cold Spring Harbor
Laboratory Press, USA, or as recommended by the manufacturer's
instruction in the cases when kits were used. PCR-cloning and
modification of the mouse variable regions have been conducted
using standard PCR methodology. Primers indicated in the respective
results section have been used.
Expression of cB-B4/nBT062
Exponentially growing COS cells, cultured in DMEM supplemented with
10% FCS, 580 .mu.g/mL-glutamine, 50 Units/ml penicillin and 50
.mu.g/ml streptomycin were harvested by trypsinisation and
centrifugation and washed in PBS. Cells were resuspended in PBS to
a final concentration of 1.times.10.sup.7 cells/ml. 700 .mu.l of
COS cell suspension was transferred to a Gene Pulser cuvette and
mixed with heavy and kappa light chain expression vector DNA (10
.mu.g each or 13 .mu.g of Supervector). Cells were electroporated
at 1900 V, 25 .mu.F using a Bio-Rad Gene Pulser. Transformed cells
were cultured in DMEM supplemented with 10% gamma-globulin free
FBS, 580 .mu.g/ml L-glutamine, 50 Units/ml penicillin and 50
.mu.g/ml streptomycin for 72 h before antibody-containing cell
culture supernatants were harvested.
Capture ELISA to Measure Expression Levels of cB-B4/nBT062
96 well plates were coated with 100 .mu.l aliquots of 0.4 .mu.g/ml
goat anti-human IgG antibody diluted in PBS (4.degree. C.,
overnight). Plates were washed three times with 200 .mu.l/well
washing buffer (PBS+0.1% Tween-20). Wells were blocked with 0.2%
BSA, 0.02% Tween-20 in PBS, before addition of 200 .mu.l cell
culture supernatants containing the secreted antibody (incubation
at 37.degree. C. for one hour). The wells were washed six times
with washing buffer, before detection of bound antibody with goat
anti-human kappa light chain peroxidase conjugate.
Purification of cB-B4/nBT062 from Cell Culture Supernatants
The cB-B4 antibody was purified from supernatants of transformed
COS 7 cells using the Protein A ImmunoPure Plus kit (Pierce,
Rockford, Ill.), according to the manufacturer's
recommendation.
cB-B4 Binding and Competition Assay
Analysis of binding activity of B-B4 and cB-B4 to CD138 was
performed using the Diaclone (Besancon, France) sCD138 kit
according to the manufacturer's recommendation, considering the
changes described in the results section.
RNA Preparation and cDNA Synthesis
Hybridoma B-B4 cells were grown and processed using the QIAGEN Midi
kit (Hilden, Germany) to isolate RNA following the manufacturer's
protocol. About 5 .mu.g of B-B4 RNA was subjected to reverse
transcription to produce B-B4 cDNA using the Amersham Biosciences
(Piscataway, N.J.) 1st strand synthesis kit following the
manufacturer's protocol.
Cloning of B-B4 Immunoglobulin cDNA
Immunoglobulin heavy chain (IgH) cDNA was amplified by PCR using
the IgH primer MHV7 (5'-ATGGGCATCAAGATGGAGTCACAGACCCAGG-3') [SEQ ID
NO:3] and the IgG1 constant region primer MHCG1
(5'-CAGTGGATAGACAGATGGGGG-3') [SEQ ID NO:4]. Similarly,
immunoglobulin light chain (IgL) was amplified using the three
different Ig.kappa. primers MKV2
(5'-ATGGAGACAGACACACTCCTGCTATGGGTG-3') [SEQ ID NO:5], MKV4
(5'-ATGAGGGCCCCTGCTCAGTTTTTTGGCTTCTTG-3') [SEQ ID NO:6] and MKV9
(5'-ATGGTATCCACACCTCAGTTCCTTG-3') [SEQ ID NO:7], each in
combination with primer MKC (5'-ACTGGATGGTGGGAAGATGG-3') [SEQ ID
NO:8]. All amplification products were directly ligated with the
pCR2.1-TOPO vector using the TOPO-TA cloning kit (Invitrogen,
Carlsbad, Calif.) according to the manufacturer's instruction.
E. coli TOP10 bacteria (Invitrogen) transformed with the ligated
pCR2.1 vector constructs were selected on LB-ampicillin-Xgal agar
plates. Small scale cultures were inoculated with single white
colonies, grown overnight and plasmids were isolated using the
QIAprep Spin Miniprep kit according to the manufacturer's
instruction.
cDNA Sequence Determination
Plasmids were sequenced using the BigDye Termination v3.0 Cycle
Sequencing Ready Reaction Kit (ABI, Foster City, Calif.). Each
selected plasmid was sequenced in both directions using the 1210
and 1233 primers cycled on a GeneAmp9600 PCR machine. The
electrophoretic sequence analysis was done on an ABI capillary
sequencer.
The complete cycle of RT-PCR, cloning and DNA sequence analysis was
repeated to obtain three completely independent sets of sequence
information for each immunoglobulin chain.
B-B4 V.kappa. DNA Sequence
1st strand synthesis was performed in three independent reactions.
The PCR products generated by using primers MKC and MKV2 (sequences
given above) were ligated into pCR2.1-TOPO vectors according to the
manufacturer's instruction. Clones from each independent set of
RT-PCR reactions were sequenced in both directions. MKV2-primed
product sequence was highly similar to sterile kappa transcripts
originating from the myeloma fusion partner such as MOPC-21, SP2
and Ag8 (Carroll et al., Mol. Immunol., 25 (1988), 991; Cabilly et
al., Gene, 40 (1985); 157) and was therefore disregarded.
The PCR products using MKC with MKV4 and MKV9 primers were similar
to each other and differed only at the wobble positions within the
leader sequence primer.
B-B4 VH DNA Sequence
1st strand synthesis was performed in three independent reactions
and PCR products were cloned and sequenced from each 1st strand
product. Five clones were sequenced from each 1st strand.
Construction of Chimeric cB-B4 Expression Vectors
The construction of the chimeric expression vectors entails adding
a suitable leader sequence to VH and V.kappa., preceded by a BamHI
restriction site and a Kozak sequence. The Kozak consensus sequence
is crucial for the efficient translation of a variable region
sequence. It defines the correct AUG codon from which a ribosome
can commence translation, and the single most critical base is the
adenine (or less preferably, a guanine) at position -3, upstream of
the AUG start. The leader sequence is selected as the most similar
sequence in the Kabat database (Kabat et al., NIH National
Technical Information Service, 1991). These additions are encoded
within the forward (For) primers (both having the sequence
5'-AGAGAAGCTTGCCGCCACCAT-GATTGCCTCTGCTCAGTTCCTTGGTCTCC-3' [SEQ ID
NO:9]; restriction site is underlined; Kozak sequence is in bold
type). Furthermore, the construction of the chimeric expression
vectors entails introducing a 5' fragment of the human gammal
constant region, up to a natural ApaI restriction site, contiguous
with the 3' end of the J region of B-B4 and, for the light chain,
adding a splice donor site and HindIII site. The splice donor
sequence is important for the correct in-frame attachment of the
variable region to its appropriate constant region, thus splicing
out the V:C intron. The kappa intron+CK are encoded in the
expression construct downstream of the B-B4 V.kappa. sequence.
Similarly, the gamma-4 CH is encoded in the expression construct
downstream of the B-B4 VH sequence.
The B-B4 VH and V.kappa. genes were first carefully analyzed to
identify any unwanted splice donor sites, splice acceptor sites,
Kozak sequences and for the presence of any extra sub-cloning
restriction sites which would later interfere with the subcloning
and/or expression of functional whole antibody. An unwanted HindIII
site was found in the V.kappa. sequence which necessarily was
removed by site-directed mutagenesis via PCR without changing the
amino acid sequence. For this reactions, oligonucleotide primers
BT03 (5'-CAACAGTATAGTAAGCTCCCTCGGACGTTCGGTGG-3') [SEQ ID NO:10] and
BT04 (5'-CCACCGAACGTCCGAGGGAGCTTACTATACTGTTG-3') [SEQ ID NO:11]
were used and mutagenesis was performed according to the Stratagene
(La Jolla, Calif.) Quickchange Mutagenesis Kit protocol.
Kappa Chain Chimerization Primers
The non-ambiguous B-B4 V.kappa. leader sequence, independent of the
PCR primer sequence, was aligned with murine leader sequences in
the Kabat database. The nearest match for the B-B4 VH leader was
VK-10 ARS-A (Sanz et al., PNAS, 84 (1987), 1085). This leader
sequence is predicted to be cut correctly by the SignalP algorithm
(Nielsen et al., Protein Eng, 10 (1997); 1). Primers CBB4Kfor (see
above) and g2258 (5'-CGCGGGATCCACTCACGTTTGATTTCCAGCTTGGTGCCTCC-3'
[SEQ ID NO:12]; Restriction site is underlined) were designed to
generate a PCR product containing this complete leader, the B-B4
V.kappa. region, and HindIII and BamHI terminal restriction sites,
for cloning into the pKN100 expression vector. The forward primer,
CBB4K introduces a HindIII restriction site, a Kozak translation
initiation site and the VK-10 ARS-A leader sequence. The reverse
primer g2258 introduces a splice donor site and a BamHI restriction
site. The resulting fragment was cloned into the HindIII/BamHI
restriction sites of pKN100.
Heavy Chain Chimerization Primers
The non-ambiguous B-B4 VH leader sequence, independent of the PCR
primer sequence, was aligned with murine leader sequences in the
Kabat database. The nearest match for the B-B4 V.kappa. leader was
VH17-1A (Sun et al., PNAS, 84 (1987), 214). This leader sequence is
predicted to be cut correctly by the SignalP algorithm. Primers
cBB4Hfor (see above) and g22949
(5'-CGATGGGCCCTTGGTGGAGGCTGAGGA-GACGGTGACTGAGGTTCC-3' [SEQ ID
NO:13]; Restriction site is underlined) were designed to generate a
PCR product containing VH17-1A leader, the B-B4 VH region, and
terminal HindIII and ApaI restriction sites, for cloning into the
pG4D200 expression vector. The forward primer cBBHFor introduces a
HindIII restriction site, a Kozak translation initiation site and
the VH17-1A leader sequence. The reverse primer g22949 introduces
the 5' end of the gamma4 C region and a natural ApaI restriction
site. The resulting fragment was cloned into the HindIII/ApaI
restriction sites of pG4D200, resulting in vector pG4D200cBB4.
Production of cBB4 Antibody
One vial of COS 7 cells was thawed and grown in DMEM supplemented
with 10% Fetal clone I serum with antibiotics. One week later,
cells (0.7 ml at 10.sup.7 cells/ml) were electroporated with
pG4D200cBB4 plus pKN100cBB4 (10 .mu.g DNA each) or no DNA. The
cells were plated in 8 ml growth medium for 4 days. Electroporation
was repeated seven times.
Detection of Chimeric Antibody
A sandwich ELISA was used to measure antibody concentrations in COS
7 supernatants. Transiently transformed COS 7 cells secreted about
6956 ng/ml antibody (data not shown).
Binding Activity of cB-B4
To assay the binding activity of cB-B4 in COS 7 culture
supernatants, the Diaclone sCD138 kit has been used, a solid phase
sandwich ELISA. A monoclonal antibody specific for sCD138 has been
coated onto the wells of the microtiter strips provided. During the
first incubation, sCD138 and biotinylated B-B4 (bio-B-B4) antibody
are simultaneously incubated together with a dilution series of
unlabeled test antibody (B-B4 or cB-B4).
The concentrations of bio-B-B4 in this assay have been reduced in
order to obtain competition with low concentrations of unlabeled
antibody (concentration of cB-B4 in COS 7 cell culture supernatants
were otherwise too low to obtain sufficient competition). Results
from this assay reveal that both antibodies have the same
specificity for CD138 (data not shown).
Purification of cB-B4
Chimeric B-B4 was purified from COS 7 cell supernatants using the
Protein A ImmunoPure Plus kit (Pierce), according to the
manufacturer's recommendation (data not shown).
K.sub.D-Determination: Comparison nBT062/BB4
Purification of Soluble CD 138
Soluble CD138 antigen from U-266 cell culture supernatant was
purified by FPLC using a 1 ml "HiTrap NHS-activated HP" column
coupled with B-B4. Cell culture supernatant was loaded in
PBS-Buffer pH 7.4 onto the column and later on CD138 antigen was
eluted with 50 mM tri-ethylamine pH 11 in 2 ml fractions. Eluted
CD138 was immediately neutralised with 375 .mu.L 1 M Tris-HCl, pH 3
to prevent structural and/or functional damages.
Biotinylation of CD 138
Sulfo-NHS-LC (Pierce) was used to label CD138. NHS-activated
biotins react efficiently with primary amino groups like lysine
residues in pH 7-9 buffers to form stable amide bonds.
For biotinylation of CD138, 50 .mu.l of CD138 were desalted using
protein desalting spin columns (Pierce). The biotinylation reagent
(EZ-Link Sulfo NHS-LC-Biotin, Pierce) was dissolved in ice-cooled
deionised H.sub.2O to a final concentration of 0.5 mg/ml.
Biotinylation reagent and capture reagent solution were mixed
having a 12 times molar excess of biotinylation reagent compared to
capture reagent (50 pmol CD138 to 600 pmol biotinylation reagent)
and incubated 1 h at room temperature while shaking the vial
gently. The unbound biotinylation reagent was removed using protein
desalting columns.
Immobilization of bCD 138
The sensorchip (SENSOR CHIP SA, BIACORE AB) used in the BIACORE
assay is designed to bind biotinylated molecules for interaction
analysis in BIACORE systems. The surface consists of a
carboxymethylated dextran matrix pre-immobilized with streptavidin
and ready for high-affinity capture of biotinylated ligands.
Immobilization of bCD138 was performed on SENSOR CHIP SA using a
flow rate of 10 .mu.l/min by manual injection. The chip surface was
conditioned with three consecutive 1-minute injections of 1 M NaCl
in 50 mM NaOH. Then biotinylated CD138 was injected for 1
minute.
K.sub.D-Determination of Different Antibodies Using BIACORE
The software of BIACORE C uses pre-defined masks, so called
"Wizards" for different experiments where only certain settings can
be changed. As the BIACORE C was originally developed to measure
concentrations, there is no wizard designed to carry out affinity
measurements. However, with the adequate settings, the wizard for
"non-specific binding" could be used to measure affinity rate
constants and was therefore used for K.sub.D-determination. With
this wizard, two flow cells were measured and the dissociation
phase was set to 90 s by performing the "Regeneration 1" with
BIACORE running buffer. "Regeneration 2" which is equivalent to the
real regeneration was performed with 10 mM Glycine-HCl pH 2.5.
After this step, the ligand CD138 was in its binding competent
state again. During the whole procedure HBS-EP was used as running
and dilution buffer. To determine binding of the different
antibodies (.about.150 kDa) to CD138, association and dissociation
was analysed at different concentrations (100, 50, 25 12.5, 6.25
and 3.13 nM). The dissociation equilibrium constants were
determined by calculating the rate constants ka and kd. Afterwards,
the K.sub.D-values of the analytes were calculated by the quotient
of kd and ka with the BIAevaluation software. The results are shown
in Table 13.
TABLE-US-00017 TABLE 13 Comparative analysis of K.sub.D values of
nBT062 and B-B4. Standard deviations are given for mean K.sub.D
values. Affinity Antibody K.sub.D (nM) mean K.sub.D (nM) nBT062 1.4
1.4 +/- 0.06 1.4 1.5 B-B4 1.7 1.6 +/- 0.06 1.7 1.6 nBT062-SPDB-DM4
1.9 1.9 +/- 0.00 1.9 1.9 B-B4-SPP-DM1 2.6 2.6 +/- 0.06 2.7 2.6
Discussion
Mean K.sub.D values for each antibody were calculated from three
independent experiments. The results show that in all measurements
nBT062 exhibits slightly decreased K.sub.D values compared to B-B4
(mean K.sub.D values were 1.4 and 1.6 nM, respectively).
Preparation of Immunoconjugates
nBT062-DM1 and huC242-DM1
The thiol-containing maytansinoid DM1 was synthesized from the
microbial fermentation product ansamitocin P-3, as previously
described by Chari (Chari et al., Cancer Res. 1 (1992), 127).
Preparation of humanized C242 (huC242) (Roguska et al., PNAS, 91
(1994), 969) has been previously described. Antibody-drug
conjugates were prepared as previously described (Liu et al., PNAS,
93 (1996), 8618). An average of 3.5 DM1 molecules was linked per
antibody molecule.
nBT062-DM4
BT062 is an antibody-drug conjugate composed of the cytotoxic
maytansinoid drug, DM4, linked via disulfide bonds through a linker
to the nBT062 chimerized monoclonal antibody. Maytansinoids are
anti-mitotics that inhibit tubulin polymerization and microtubule
assembly (Remillard et al., Science 189 (1977), 1002). Chemical and
schematic representations of BT062 (nBT062-DM4) are shown in FIGS.
1 and 2.
FACS Analysis and WST Cytotoxicity Assays
FACS Analysis
OPM-2 cells are plasma cell leukaemia cell lines showing highly
expressing CD138. OPM-2 cells were incubated with nBT062,
nBT062-SPDB-DM4, nBT062-SPP-DM1 or nBT062-SMCC-DM1 at different
concentrations (indicated in FIG. 6). The cells were washed and
CD138-bound antibody or conjugates were detected using a
fluorescence-labelled secondary antibody in FACS analysis. The mean
fluorescence measured in these experiments was plotted against the
antibody concentration.
Cell Viability Assay
CD138.sup.+ MOLP-8 cells were seeded in flat bottom plates at 3000
cells/well. CD138.sup.- BJAB control cells were seeded at 1000
cells/well. The cells were treated with nBT062-SPDB-DM4,
nBT062-SPP-DM1 or nBT062-SMCC-DM1 at different concentrations
(indicated in FIG. 7) for five days. WST reagent (water-soluble
tetrazolium salt, ROCHE) was added in order to measure cell
viability according to the manufacturer's instruction (ROCHE). The
reagent was incubated for 7.5 h on MOLP-8 cells and for 2 h on BJAB
cells. The fraction of surviving cells was calculated based on the
optical densities measured in a microplate reader using standard
procedures.
Discussion
Binding of nBT062-SPDB-DM4, nBT062-SPP-DM1, nBT062-SMCC-DM1 or
nBT062 was analyzed by FACS. CD138.sup.+ OPM-2 as target cells were
incubated with nBT062 or immunoconjugates and cell-bound molecules
were detected using a fluorescence-labeled secondary antibody. In
FIG. 6, the mean fluorescences as measure for the amount of cell
bound antibody is plotted against different antibody or conjugate
concentrations. The results show, that nBT062-SPDB-DM4,
nBT062-SPP-DM1 and nBT062-SMCC-DM1 show very similar binding
characteristics. In addition, the results strongly suggest that the
binding characteristics of the unconjugated antibody is not
affected by the conjugated toxins.
In cell viability assays, the cytotoxic activity of the antibody
against CD138.sup.+ MOLP-8 target cells and against CD138.sup.-
BJAB B-lymphoblastoma control cells were analyzed. Both cell lines
were seeded in flat-bottom plates and incubated with increasing
concentrations of the immunoconjugates. Unconjugated antibody was
used as a control. The cytotoxic activity was analyzed five days
after addition of the immunoconjugates by using WST reagent in
order to measure cell viability. In FIG. 7 (A)-(C), the fraction of
surviving cells relative to control cells treated with vehicle
control is plotted against increasing immunoconjugate
concentrations. The results show that cytotoxic activity of
nBT062-SPDB-DM4, nBT062-SPP-DM1 and nBT062-SMCC-DM1 against MOLP-8
cells is very similar. As expected, CD138.sup.- BJAB control cells
were not killed by the immunoconjugates, indicating that all
immunoconjugates act via cell specific binding to CD138. In
competition experiments, in which MOLP-8 cells were preincubated
with a molar excess of unconjugated nBT062. Preincubation
substantially blocked the cytotoxicity of nBT062-SPDB-DM4,
providing further evidence that the immunoconjugates kill the cells
via specific binding to CD138 onto the cell surface (FIG. 7
(D)).
Indicator: Pancreas/Mammary and Other Carcinoma--Xenograft Models
General Experimental Set-up
In accordance with the CD138 expression analysis
(Immunohistochemistry analysis on tumor tissue microarrays) tumor
candidates were selected from a primary tumor collection, that is,
from patient derived tumors. These tumors display similar
characteristics as the patient tumors, since they are passaged in
mice at low numbers, to retain original characteristics. Following
subcutaneous transplantation and establishment of tumors (induction
time 30 days), the immunoconjugate BT062 was injected intravenously
at 2 different concentrations of the maytansinoid DM4, 450 .mu.g/kg
and 250 .mu.g/kg (each based on the molecular weight of the linked
DM4 (1 mg of DM4 is conjugated to 52 mg of antibody, equalling a
total mass of 53 mg; 450 .mu.g/kg DM4=23.850 .mu.g) The
immunoconjugate was administered once weekly for 10 weeks (in case
of treatment of pancreatic tumor implanted mice) and 5 weeks (in
case of mammary, lung and bladder tumor implanted mice). A
treatment free observation period followed to investigate a
possible tumor regrowth.
EXAMPLE 1
Pancreas Carcinoma
Pancreatic tumor tissue (PAXF 736 (Kuesters et al., 2006) was
implanted (bilateral) into NMRI mice. The implanted tumor
originated from a patient's primary pancreatic carcinoma (poorly
differentiated, infiltrating adenocarcinoma (an exocrine
carcinoma)). No side effects were observed. The tumor of this
patient was identified as a high CD138 expressing tissue by
immunohistochemistry studies. However, CD138 is not expressed to a
degree comparable to myelomatous plasma cells in multiple myeloma
patients, as detected on tumorgenic cell lines by flow cytometric
surface staining.
Treatment with BT062 was initiated after tumors have reached a size
of approx. 6-8 mm diameter (minimum 5 mm). Tumor diameters have
been measured two times a week. Tumor volumes were calculated
according to the formula a.times.b.times.b/2 where "a" is the
longest axis and "b" the perpendicular axis thereto. Inhibition of
tumor volume in the test groups relative to the vehicle control
group was calculated as the ratio of the median relative tumor
volumes (T/C).
Tumor inhibition for a particular day (T/C in %) was calculated
from the ratio of the median RTV (relative tumor volume) values of
test versus control groups multiplied by 100%.
.function..times..times..times..times..times..times..times..times..times.-
.times..times..times..times..times..times..times..times..times..times..tim-
es..times..times..times..times..times..times..times..times..times..times..-
times..times..times..times. ##EQU00002##
Tumor volume could be significantly reduced by this weekly
administration of BT062. As can be seen in FIG. 8, dose dependent
partial and complete remission was observed. The Figure shows that
at a dose of 23.85 mg/kg, complete remission could be obtained 28
days after tumor implantation, while at a dose of 13.25 mg/kg,
complete remission could be obtained 35 days after tumor
implantation. Notably, after 52 days all mice in the 13.25 mg/kg
administration regimens were still alive (8/8), while the eight
mice of the control group had been reduced to 1. A T/C value below
10% indicates complete remission (CR) (Bissery et al., 1991).
According to this criteria, CR was achieved in both treatment
groups, reflecting the complete remission that was achieved by
BT062. Remarkably in a treatment free observation phase, no tumor
regrowth was detected, confirming the complete curance of in this
model.
TABLE-US-00018 TABLE 14 Tumor volume is pancreatic cancer xenograft
mouse model Relative Tumor Volume (%) Day 52: Mean (.+-.) Range T/C
(%) Control 2055 2055 BT062-DM4; 0 (.+-.1.0) 0-3.5 0.0 13.25 mg/kg
BT062-DM4; 0 (.+-.0.01) 0-0.1 0.0 23.85 mg/kg
EXAMPLE 2
Mammary Carcinoma
NMRI (nude) mice were implanted (bilateral) with primary mammary
tumor of a patient (determined via IHC analysis as strongly CD138
positive). A breast carcinoma skin metastasis was taken at stage
M1. It was a tumor which did not respond to Herceptin (low
Her.sub.2 with an intermediate expression). The tumor was estrogen
receptor negative and progesterone receptor negative and thus not
responsive towards hormone therapy. Tumors to be implanted were
selected according to IHC staining results (strong, homogenous
expression of CD138 detected by BT062 (triple negative expression
of hormone receptors estrogen and progesterone); Her.sub.2
expression scored 2 or less (regarded as Herceptin non
responsive).
Treatment with BT062 was initiated after tumors had reached a size
of approx. 100 mm.sup.3. Tumor volumes were calculated according to
the formula a.times.b.times.b/2, with "a" being the longest axis
and "b" the perpendicular axis thereto. Inhibition of tumor volume
in the test groups relative to the vehicle control group was
calculated as the ratio of the median relative tumor volumes (T/C).
BT062 was administered once weekly at a loading dose of 13.25 mg/kg
(which was given on day 1) followed by doses of 4 mg/kg once
weekly. In the other dose group a high dose of 23.85 mg/kg was
administered.
Tumor volume could be significantly reduced by weekly
administration of BT062. A dose dependent partial and complete
remission was observed. The immunoconjugate was well tolerated,
having no influence on body weight after each injection. A T/C
value below 10% was obtained in both treatment groups, reflecting a
complete remission achieved by the administration of BT062. As can
be seen in FIG. 9, the anti-tumor effect (i.e., complete remission)
was achieved after 21 days, which can be considered a rapid
response to BT062. As can been seen from FIGS. 35 and 36, lower
dose regimens were also effective. As can been seen from FIG. 37, a
mouse model that did not respond to Docetaxel treatment, also did
not respond to BT062 treatment, while a model that did not respond
to taxol responded well to BT062 treatment (FIG. 35).
Compared to the pancreatic model, duration of treatment could be
cut short by half (5 weeks instead of 10 weeks) and the low dose of
13.25 mg/kg was reduced to 4 mg/kg to achieve a similar effect,
namely complete remission and no tumor regrowth. The shorter
treatment period for mammary carcinoma was not expected, since on
IHC analysis the level of CD138 expression was similar. Thus, no
conclusions can be drawn from the level of CD138 expression to a
general recommendation for the treatment duration. After 21 days
all mice of both the treated groups as well as the control group
were still alive. In a treatment free observation period (39 days
after the last administration of the immunoconjugate) no tumor
regrowth was detected, confirming the complete curance.
TABLE-US-00019 TABLE 15 Tumor volume is mammary carcinoma xenograft
mouse model. Relative Tumor Mean Volume (%) (Day 21) Range T/C
Control (PBS) 533 (.+-.149.5) 339-878 BT062-DM4; 0 (.+-.0.02) 0-0.1
0.0 13.25 mg/kg/4 mg/kg BT062-DM4; 0 (.+-.1.75) 0-6.6 0.0 23.85
mg/kg
TABLE-US-00020 TABLE 16 Expression of CD138 on mammary carcinoma
cells vs. epithelium cells Staining score (membrane) FFPE tissue
samples 0.25 .mu.g/ml 0.05 .mu.g/ml Breast, tumor 3 Homo 2-3 Homo
Mets, -061909-13 Breast, tumor 2-3 Homo 1-2 Hetero Unknown,
-061909-12 Breast, tumor 3 Hetero 2 Focal Mets, -061909-09 Breast,
tumor 3 Hetero 1-3 Hetero Primary, -111904-4 Breast, tumor 3 Hetero
1 Hetero Primary, -111904-1 Normal Skin sample 1 3 Homo 3 Homo
Normal Skin sample 1 3 Homo 3 Homo
EXAMPLE 3
Bladder Carcinoma
NMRI (nude) mice are implanted with a bladder tumor (determined via
IHC analysis as CD138 strong positive), namely a transitional cell
carcinoma.
Treatment with BT062 is initiated after tumors had reached a size
of approx. 100 mm.sup.3. Tumor volumes are calculated according to
the formula a.times.b.times.b/2, with "a" being the longest axis
and "b" the perpendicular axis thereto. Inhibition of tumor volume
in a test groups relative to the vehicle control group is
calculated as the ratio of the median relative tumor volumes
(T/C).
Tumor volume is sought to be significantly reduced by weekly
administration of BT062. Any dose dependent partial and complete
remission is tracked.
EXAMPLE 4
Lung Carcinoma
NMRI (nude) mice are implanted with a Lung carcinoma (determined
via IHC analysis as CD138 strong positive).
Treatment with BT062 is initiated after tumors had reached a size
of more than 5 mm. Tumor diameters are measured two times a week.
Tumor volumes are calculated according to the formula a*b*b/2, with
"a" being the longest axis and "b" the perpendicular axis thereto.
Inhibition of tumor volume in a test groups relative to the vehicle
control group is calculated as the ratio of the median relative
tumor volumes (T/C).
Complete remission could be achieved in both dose groups (4 mg/kg
and 23.85 mg/kg once per week). In a treatment free period, no
re-growth was observed, confirming the complete eradication of the
tumors.
EXAMPLE 5
To investigate metastatic tumors, NMRI (nude) mice were implanted
with a metastatic patient tissues derived from a bladder tumor
(determined via IHC analysis as CD138 strong positive).
Complete remission could be also achieved in this model, in both
dose groups (4 mg/kg and 23.85 mg/kg once per week). In a treatment
free period, no re-growth was observed, confirming the complete
eradication of the tumors.
EXAMPLE 6
To investigate efficacy of BT062 at lower doses and in comparison
with a clinically used drugs taxol (Paclitaxel), NMRI (nude) mice
were implanted with the mammary tumor of example 2. Lower doses of
BT062 (0.5 mg/kg, 1 mg/kg, 2 mg/kg and 4 mg/kg) were administered
once weekly (FIG. 35). At 4 and 2 mg/kg once weekly, a complete
remission was observed, without re-growth in a treatment free
period. Taxol treated mice showed only a minor tumor growth delay
at 10 mg/kg. DM4 was used in an amount corresponding to that in 4
mg BT062, but did not result in tumor response. At concentrations 1
mg/kg a "tumor stasis" could be achieved, i.e. the tumor neither
grow but the volume did not decrease. This is also called the
minimal effective dose, since in this group 2/7 mice had a partial
remission and 3/7 mice had complete remission without tumor
regrowth.
The minimal effective dose can also be somewhat lower than 1 mg/kg
but higher than 0.5 mg/kg.
EXAMPLES 7 AND 8
Here BT062 was investigated at lower doses and compared with the
clinically used drug docetaxel (10 mg/kg), as in Example 6. Lower
doses of BT062 (1 mg/kg, 2 mg/kg, 4 mg/kg and 8 mg/kg) were
administered once weekly. At 8 mg/kg once weekly, a complete
remission was observed during treatment in mice that had tumors
showing a 2-3 scored CD138 IHC staining and that also response to
docetaxel, while mice that had tumors showing a 1-2 scored IHC
staining and did not respond to docetaxel, also did not respond to
BT062 (FIGS. 36 and 37).
EXAMPLE 9
To investigate efficacy of BT062 at lower doses and in comparison
with a clinically used used drug docetaxel (10 mg/kg) NMRI (nude)
mice were implanted with a primary pancreatic tumor. The patient
derived tumor had a high but heterogeneous CD138 staining
determined by IHC analysis and scored with 3. Lower doses of BT062
(1 mg/kg, 2 mg/kg, 4 mg/kg and 8 mg/kg) were administered once
weekly (FIG. 38). At 4 and 8 mg/kg once weekly, a complete
remission was observed, but re-growth in a treatment free period
occurred which could be an effect of the heterogeneity of the
tumor. Docetaxel treated mice showed complete remission during the
treatment period as well as the treatment free period.
Human Trials with BT062
In the context of the present invention, human subjects responded
well to a low dose regime. This was even the case in absence of any
additional treatments that would compensate for potential
variations in qualitative or quantitative expression of the CD138
on the target cells (compare MYLOTARG). While mouse models
demonstrated that BT062 has highly significant antimyeloma activity
at doses that are well tolerated in mice, effectiveness was
considerably better at relatively high doses (results not shown),
posing the question how higher doses would be tolerated by human
subjects that express CD138 on a wide variety of non-tumor
cells.
Phase I Research Study
This study was performed to test the effects (good and bad) and to
determine the MTD (maximum tolerated dose) of BT062 in treating
patients with relapsed or relapsed refractory multiple myeloma.
Up to now, 32 patients were recruited. At least 12 out of 32
patients experienced diminished disease progression as represented
by receiving at least a forth treatment cycle. The trial is being
performed at different sites, with groups of 3 and 4 patients being
treated with different dose levels (10 mg/m.sup.2, 20 mg/m.sup.2,
40 mg/m.sup.2, 80 mg/m.sup.2, 120 mg/m.sup.2, 160 mg/m.sup.2, 200
mg/m.sup.2) for anywhere between 1 to 31 treatment cycles (results
not shown). As the person skilled in the art will appreciate a
higher number of treatment cycles is possible and within the scope
of the present inventions, such as 10 to 50, 10 to 100, 10 to 200
and more.
Disease progression diminished with relatively low dosage levels,
namely 20 mg/m.sup.2, 40 mg/m.sup.2, 80 mg/m.sup.2 and 120
mg/m.sup.2, with one patient at the 2.sup.nd dosage level of 20
mg/m.sup.2 displaying no disease progression for 10 treatment
cycles of 21 days. In some patients stable disease and responses,
including minor and partial responses could be observed.
At these dose levels, as described above (see Tables 9 and 10),
rapid clearance of BT062 from plasma was also observed. Some
pharmacokinetic profiles of these low dose administration schemes
are shown in FIG. 13. Doses of 160 mg/m.sup.2 and 200 mg/m.sup.2
were also administered. A dose of 160 mg/m.sup.2 was identified as
MTD and studies in this group were expanded. A dose of 200
mg/m.sup.2 was identified as MAD.
Repeated single doses regimens of 10 mg/m.sup.2, 20 mg/m.sup.2, 40
mg/m.sup.2, 80 mg/m.sup.2, 120 mg/m.sup.2, 160 mg/m.sup.2, 200
mg/m.sup.2 were performed every 21 day, meaning on day 1, day 22,
day 43, day 64, day 85, day 106, and so forth. The disease has been
and will be monitored by physician's assessment of hematology,
clinical symptoms and clinical chemistry as well as by measuring
M-Protein levels in the serum and urine of patients (in g/dL) and
free light-chain (FLC) levels in the serum of patients over time
(results not shown).
Immunoglobulin Assessment
The amount of 1 g antibodies including the determination of IgG
subgroups was analyzed at screening.
M-Protein Quantification and Serum Free Light Chain Assay
Initially, the response to treatment was evaluated at day 1 of
treatment cycles 1-3 by M-protein quantification using
immunoelectrophoresis (IEP) and immunofixation electrophoresis
(IFE) from serum and 24-hour urine collection. For treatment cycles
3 and beyond, M-protein quantification was performed at the Day 15
visit in order for the results to be available to assess response
prior to initiating the next treatment cycle. A general
quantitative immunoglobulin assessment was done together with
M-protein quantification.
Serum samples were used to perform FLC assays to examine multiple
myeloma subjects with no detectable M-protein
(nonsecretory/oligosecretory myeloma) and to allow for detection of
early response to treatment. Therefore serum FLC assays were
performed on day 1, 2, 3, and 8 of treatment cycle 1, on day 2, 3,
8 and 15 of cycle 4, as well as on day 1, 8 and 15 of all other
treatment cycles. M-protein and FLC were be analyzed at the
screening and at the close-out visit. Evaluations at day 1 of cycle
1 served as baseline values.
TABLE-US-00021 Dose mg/m.sup.2 Urine/Serum M-protein measurements
and FLC measurements 20 During first seven cycles disease
stabilization based on clinical symptoms and serum FLC, Urine
M-Protein decreased after 8.sup.th treatment M-Protein criteria for
Minor Response reached after 8.sup.th treatment Decrease in Urine
M-Protein level from baseline by more than 50% Diseases progression
after Cycle 10 Serum M-Protein between 0.06 and 0.1 g/dL (defined
as not measurable) 40 Stable disease for 14 weeks Serum M-Protein
decreased after 1.sup.st treatment and stabilized for 14 weeks
Diseases progression observed after treatment was held at the start
of cycle 6 (day 105) Urine M-Protein increased from 0 at screening
to a maximum of about 16 mg/24 h (defined as not measurable) 160
Serum FLC level increased during the screening period starting -21
days before day 1 of the treatment Serum FLC level decreased very
soon after 1.sup.st treatment and was already close to 25% decrease
at day 8 In comparison to baseline, FLC levels are reduced by about
40% during 1.sup.st cycle and by more than 50% after 2.sup.nd,
3.sup.rd and 4.sup.th treatment FLC criteria for Partial Response
were reached very early Disease progression after the end of the
4.sup.th treatment cycle Serum M-Protein not measurable = 0; Urine
M-Protein decreased from 140 mg/24 h at baseline to 120 mg/24 h
before 2.sup.nd treatment (defined as not measurable) => non-
secretory Myeloma
Table 17 provides observations made regarding Urine/Serum M-protein
and serum FLC measurements in selected patients in a repeated
single dose regime. In a repeated single dose regimen of BT062,
DLTs were observed in the mucosa of patients treated in the 200
mg/m.sup.2 dose group. The target for BT062 (CD138) is expressed in
the mucosa and toxicities in these tissues and organs con be
considered as target related. Serious adverse events, not
qualifying for DLT, were observed in eye patients. However, the eye
toxicity is suggested to be rather related to the effector compound
since this is a typical toxicity also found with other DM4
conjugates such as SAR3419, or IMGN388 that do not target CD138.
This eye toxicity occurred in one patient in the repeated single
dose study 3 days after the 3rd cycle and in the other patient 4
days after the 4.sup.th cycle. In the maximal administered dose
group (160 mg/kg) of the repeated single dose study, CD138 related
toxicities occurred during the first days but also after repeated
cycles, most of them were considered mild to moderate.
TABLE-US-00022 Urine/Serum M-protein measurements and FLC Dose FIG.
measurements 3 .times. 50 mg/m2 20 Serum M-Protein decrease for 6
cycles: At least stable disease could be achieved over 6 cycles,
with a decrease of serum M protein by nearly 25% during/after 3rd
and 5th treatment cycle 3 .times. 65 mg/m2 21 Free lambda-kappa
light chain A strong decrease of the serum FLC level could be
observed after just a single treatment cycle 3 .times. 120
mg/m.sup.2 24 Urine M-Protein decrease A decease of urine M protein
after first and repeated cycles, with a reduction of more than 50%
achieved after 3rd, 7th and 10th cycle
Table 18 provides observations made regarding Urine/Serum M-protein
and serum FLC measurements in selected patients in a repeated
multiple dose regimen.
Determination of BT062 and DM4 from Plasma
To assess single dose PK properties of BT062, after IV
administration of BT062, extensive plasma sampling was performed
during the first treatment cycle. The same evaluation was performed
during treatment cycle 4. To a lesser extent plasma samples were
also obtained at day 1 and 8 of all other treatment cycles, as well
as on close-out and follow-up visit. The amount of BT062 in the
plasma is determined via a PK ELISA method described as
follows:
Experimental Description:
The wells of a microtiter plate are first coated with
anti-maytansinoid (anti-DM4) antibody overnight at 2-8.degree. C.
and after blocking with assay buffer (0.5% BSA/TBS) incubated on
the next day with plasma samples. These are diluted beforehand at
least 1:100 in assay buffer. BT062 antibodies contained in the
samples are bound by the anti-DM4 antibody immobilized in the
plates. After incubation, unbound material is removed by washing.
Then, a HRP-conjugated secondary antibody is added, which binds to
the BT062 antibodies. Unbound secondary antibody is removed by
another washing step. After this, TMB substrate solution is
pipetted into all the wells. A color reaction develops proportional
to the amount of BT062 bound during incubation of the sample. The
color reaction is ended using a stop solution, which causes the
color to change from blue to yellow. The final measurement is
carried out with a photometer at a wavelength of 450 nm.
The relationship between concentration and optical density is
evaluated using Magellan V6.6 software. If samples from clinical
trials are measured (plasma samples from multiple myeloma
patients), for each patient an individual standard curve should be
prepared in 1:100 diluted "predose" plasma (plasma before treatment
with BT062). If in addition to the obligatory 1:100 dilution in
assay buffer, a clinical test sample has to be diluted further (due
to a high BT062 concentration), this dilution should be prepared in
1:100 diluted predose plasma (of the patient concerned). For
stability tests (e.g. freezing/thawing stability, storage
stability), the BT062 standard and also corresponding samples or
in-process controls are prepared in 1:100 diluted heparin plasma
pool.
Determination of Shed CD138 and NAPA
All pre-dose plasma samples were evaluated for levels of
shed/soluble CD138 (sCD138) to investigate a potential correlation
between levels of sCD138 and antitumor activity. These measurements
also allowed to determine that the lower than expected Cmax values
are not dependent on the amount of sCD138 present prior to
administration of BT062 (see FIG. 17). Predose plasma samples from
day 1 of each treatment cycle and from close out and follow-up
visit were evaluated for the presence of humoral responses against
BT062 (drug product) by assessment of human antiproduct antibodies
(HAPA).
Shed CD138 Measurements Observed
In Myeloma patients high levels of sCD138 can be observed and might
be an indicator of prognosis of myeloma patients (Maisnar et al.,
2005).
Patients with MGUS and MM might display high levels of soluble
CD138 concomitant with higher levels of .beta.2-microglobulin and
elevated plasma cell content in the bone marrow (Aref et al.,
2003).
A kit was used for determining soluble CD138. Surprising, it was
found that one patient (identified as 003-003) treated at 20
mg/m.sup.2 of BT062 displayed a minor response with regard to urine
M-protein levels, although this patient displayed high levels of
sCD138 before treatment.
Soluble (s) CD138 values were determined in different subjects.
TABLE-US-00023 TABLE 19 Patient 003-003 (repeated single dose 20
mg/m.sup.2) displayed very high values of sCD138. Nonetheless, this
patient achieved a minor response in M-Protein level. Subject
sCD138 (ng/ml) 002-003 61.3 001-002 196 002-004 56.7 003-003 2583
Mean 724.1
Combination Studies In a Phase I/IIa Multi-Dose Escalation Study,
BT062 was Combined with Lenalidomide and Dexamethasone in Subjects
with Relapsed or Relapsed/Refractory Multiple Myeloma.
One treatment cycle consisted of 28 days, or in other words, 21
days of active treatment followed by 7 days without treatment
(resting period). BT062 was administered on days 1, 8 and 15 at a
concentration of 80 mg/m.sup.2, lenalidomide (Len) (25 mg) was
administered once daily on days 1-21 and dexamethasone (Dex) (40
mg) was administered on days 1, 8, 15 and 22. Day 1 treatment of
BT062 at all cycles should concurred with day 1 of Len and
dexamethasone. As can be seen from FIG. 34, a minor response was
observed after the first treatment cycle and was maintained at the
start of the 4.sup.th cycle (day 99), even though start of cycle 2
and 3 was delayed by one week and treatment with BT062 was skipped
on day 85 and treatment with Len was skipped on days 85 to 91 and
the Dex dose was reduced to 20 mg/m.sup.2 during cycle 3. As is
clear to the person skilled in the art, either Lenalidomide,
dexamethasone or BT062 concentrations may be lowered depending on
toxicities and efficacy. Efficacy is assessed body fluids,
preferably via efficacy blood parameters such as M-Protein or FLC
(depending on the MM disease type), or other markers from body
fluids or bone marrow reflecting disease status.
With this treatment regime disclosed here, combination with Len/Dex
is possible with lower toxicities, or in combination with this
immunoconjugate, administration of the combination partners can be
adjusted e.g. lowered to minimize the toxicities associated with
their administration. Since this regimen provides better
tolerability it is applicable for combination with other drugs,
having lower or at least not higher numbers of toxicities but the
same or even better efficacy.
Possible anti-myeloma drug candidates have been evaluated as
combination partners for BT062 in cell lines:
Cell Line Studies
Combination studies in xenograph mouse models were preceded by
studies in cell lines. The synergy determination in different cell
lines was performed according to Chou and Talley (1984), using the
median effect analysis. Here, IC.sub.50 values for the cytotoxic
effects for each drug and each cell line are calculated, and then
IC.sub.50 ratios for each drug pair. The cells were then exposed to
dilution series of either these drug mixtures, or the drugs alone.
Experimental data were analyzed using the CompuSyn software
(ComboSyn, Inc., Paramus, N.J.). Combination Indexes (CI) for each
independent experiment were calculated and reported separately. In
the analysis, CI less than 1, equal to 1 and more than 1 indicates
synergy, additivity and antagonism, respectively. According to the
classification of T.C. Chou (CompuSyn, User's guide, 2004), the
author of the method, the scale of synergism and antagonism is as
follows:
TABLE-US-00024 Combination Index Description <0.1 Very strong
synergism 0.1-0.3 Strong synergism 0.3-0.7 Synergism 0.7-0.85
Moderate synergism 0.85-0.9 Slight synergism 0.9-1.1 Nearly
additive 1.1-1.2 Slight antagonism 1.2-1.45 Moderate antagonism
1.45-3.3 Antagonism 3.3-10 Strong antagonism >10 Very strong
antagonism
TABLE-US-00025 TABLE 20 Estimates of synergistic results obtained
in cell lines according to the method of Chou and Talalay (1984).
Cells Drug RPMI 8226 MOLP8 U266 Bortezomib Additive Slightly
antagonistic Antagonistic Thalidomide Additive to Additive to
slightly Antagonistic synergistic antagonistic Lenalidomide
Synergistic Additive to Slightly to synergistic moderately
antagonistic Melphalan Additive to Slightly to Additive to
synergistic moderately slightly antagonistic synergistic
Dexamethasone Not determined additive additive
In this example MOLP 8 cell lines were used for combination of
BT062 with bortezomib, thalidomide, lenalidomide, melphalan and
dexamethasone.
Combination with thalidomide or bortezomib, did neither result in a
synergistic nor an additive effect, but rather an antagonistic
effect. In contrast to these cell culture studies combination with
bortezomib was synergistic in the xenograft model described
below.
Possible anti-myeloma drug candidates have been evaluated as
combination partners for BT062 in Xenograft studies using MOLP8
human multiple myeloma cells.
EXAMPLE 1
Anti-Myeloma Effect of Combination Therapy with BT062 and
Lenalidomide
Female SCID mice were subcutaneously inoculated with MOLP 8 human
myeloma cells. Treatment with BT062 alone or in combination with
Lenalidomide was initiated day 11 post tumor inoculation. BT062 was
used in concentrations of 100 .mu.g, 200 .mu.g and 400 .mu.g alone
and in combination with Lenalidomide which was dosed
intraperitoneally at 100 mg/kg on days 1 to 5 and days 8 to 12. A
control group of animals received phosphate buffered saline (PBS)
using the same schedule and route of administration. Tumor growth
was monitored by measuring tumor size and calculated with the
formula length.times.width.times.height.times.1/2, determined on
days 10, 14, 18 and 21.
Synergism was calculated as follows (Yu et al., 2001; Gunaratnam et
al., 2009): RATIO(r)=expected FTV(combination)/observed
FTV(combination)
FTV: Fractional tumor volume=mean tumor volume (test)/mean tumor
volume (control)
A ratio>1 is regarded as synergistic, whereas r<1 is less
than additive.
The ratio (r) is, when above 1, referred to herein as "SYNERGY
RATIO."
As can be seen from Table 21 synergism was observed after 28 days
in concentrations of BT062 of 200 .mu.g and 400 .mu.g:
TABLE-US-00026 TABLE 21 Fractional tumor volume in MOLP 8
xenografts. BT062 BT062 100 + Len BT062 100 + ratio Days 100
Lenalidomide (observed) Len expected (exp/obs) 10 0.93 1.00 0.97
0.93 0.96 14 0.75 0.82 0.59 0.61 1.04 17 0.52 0.45 0.23 0.23 1.02
21 0.53 0.42 0.19 0.22 1.19 24 0.44 0.55 0.18 0.24 1.30 28 0.33
0.46 0.17 0.15 0.90 BT062 BT062 200 + Len BT062 100 + ratio 200
Lenalidomide (observed) Len expected (exp/obs) 10 1.02 1.00 1.00
1.02 1.02 14 0.45 0.82 0.51 0.37 0.73 17 0.13 0.45 0.14 0.06 0.41
21 0.08 0.42 0.07 0.03 0.45 24 0.11 0.55 0.06 0.06 1.08 28 0.13
0.46 0.03 0.06 1.86 BT062 BT062 400 + Len BT062 100 + ratio 400
Lenalidomide (observed) Len expected (exp/obs) 10 0.94 1.00 0.91
0.95 1.04 14 0.44 0.82 0.24 0.36 1.49 17 0.09 0.45 0.06 0.04 0.63
21 0.04 0.42 0.04 0.02 0.44 24 0.04 0.55 0.03 0.02 0.80 28 0.04
0.46 0.01 0.02 1.43 Different concentrations of BT062 either alone
or in combination with Lenalidomide have been administered into
tumor bearing xenograft. FTV represents the relative tumor volume.
Synergistic effects are determined using Ratio values expected FTV
versus observed FTV. A ratio >1 indicates synergy.
TABLE-US-00027 TABLE 22 Lenalidomide BT062 combination: effects at
different dosages. Tumor free Dosage per Total T/C (%) Regressions
survivors Agent injection dose (DAY 17) Partial Complete day 77
Result PBS (0.2 ml) -- -- 0/6 0/6 0/6 BT062 100 ug/kg 100 ug/kg 35
0/6 0/6 0/6 Active BT062 200 ug/kg 200 ug/kg 14 0/6 0/6 0/6 Active
BT062 400 ug/kg 400 ug/kg 9 4/6 1/6 0/6 highly active lenalidomide
100 mg/kg 1 g/kg 31 0/6 0/6 0/6 Active BT062 100 ug/kg 100 ug/kg 19
0/6 0/6 0/6 Active lenalidomide 100 mg/kg 1 g/kg BT062 200 ug/kg
200 ug/kg 12 2/6 0/6 0/6 Active lenalidomide 100 mg/kg 1 g/kg BT062
400 ug/kg 400 ug/kg 6 5/6 4/6 0/6 highly Lenalidomide 100 mg/kg 1
g/kg active
FIGS. 30 and 31 show the effect of the combination therapy on
median tumor volume (TV) in a xenograft mouse model. The result in
FIG. 30 show additive effects of the combination. Notably the
combination resulted in a dose of 100 .mu.g/kg of the
immunoconjugate, when combined with a dose of 100 mg/kg
lenalidomide. For synergy ratios, please refer to the table
above.
EXAMPLE 2
Anti-Myeloma Effect of Combination Therapy with BT062 and
VELCADE
VELCADE has been evaluated as potential multiple myeloma drug
combination partner for BT062 in Xenograft studies using MOLP8
multiple myeloma cells (IMGN Inc.). Treatment with BT062 alone or
in combination with VELCADE was initiated 11 days past tumor
implantation. BT062 was used in concentrations of 100 .mu.g, 200
.mu.g and 400 .mu.g alone and in combination with VELCADE which was
dosed at 100 mg/kg on days 1, 4, 8 and 11. A control group of
animals received phosphate buffered saline (PBS) using the same
schedule and route of administration. Tumor growth was monitored by
measuring tumor size and calculated with the formula
length.times.width.times.height.times.1/2, determined on days 10,
14, 17, 21, 24 and 28, respectively.
Synergism was calculated as in Example 1 of the combination
studies.
As can be seen from Table 23, synergy is observed in the
combination BT062 with VELCADE at day 25 in all BT062 dose
regimens. R values reported in the literature are even higher (Yu
et al., 2001).
TABLE-US-00028 TABLE 23 Combination treatment with VELCADE. BT062
BT062 100 + ratio Day 100 Velcade Velcade (observed) expected
(exp/obs) 10 1.06 1.05 1.04 1.12 1.07 14 0.74 0.84 0.56 0.62 1.11
18 0.44 0.96 0.28 0.42 1.54 21 0.39 0.80 0.23 0.31 1.38 25 0.48
0.95 0.26 0.46 1.75 BT062 BT062 200 + Vel ratio Days 200 Velcade
(observed) expected (exp/obs) 10 1.02 1.05 1.07 1.12 1.07 14 0.52
0.84 0.45 0.44 0.98 18 0.13 0.96 0.10 0.12 1.19 21 0.10 0.80 0.05
0.08 1.47 25 0.10 0.95 0.04 0.09 2.09 BT062 BT062 400 + Vel synergy
ratio Days 400 Velcade (observed) expected (exp/obs) 10 1.09 1.05
1.04 1.15 1.10 14 0.45 0.84 0.43 0.38 0.88 18 0.08 0.96 0.09 0.08
0.89 21 0.05 0.80 0.04 0.04 0.98 25 0.04 0.95 0.02 0.03 1.36
Fractional tumor volume (FTV) represents the mean tumor volume
(test)/mean relative tumour volume (control). Ratio of expected FTV
(combination) vs. observed FTV (observed). Ratio value >1
indicate synergy, values less than 1 indicate an additive
effect.
TABLE-US-00029 TABLE 24 VELCADE BT062 combination: effects at
different dosages. Treatment days Tumor free Dosage per (TX start
date = T/C (T-C) log cell Regressions survivors Agent injection day
10 post inoc.) (%) in days kill Partial Complete day 67 Result PBS
(0.2 ml) Day 1 -- -- -- 0/6 0/6 0/6 BT062 100 ug/kg Day 1 43 5.5
0.5 0/6 0/6 0/6 Inactive BT062 200 ug/kg Day 1 11 14.5 1.3 1/6 0/6
0/6 Active BT062 400 ug/kg Day 1 7 31.5 2.8 4/6 2/6 0/6 highly
active Velcade 1 mg/kg days 1, 4, 8, 11 100 0.5 0.0 0/6 0/6 0/6
Inactive BT062 100 ug/kg Day 1 20 10.5 0.9 1/6 0/6 0/6 Active
Velcade 100 mg/kg days 1, 4, 8, 11 BT062 200 ug/kg Day 1 7 23.5 2.1
4/6 1/6 0/6 highly Velcade 100 mg/kg days 1, 4, 8, 11 active BT062
400 ug/kg Day 1 7 36.5 3.2 6/6 0/6 0/6 highly active
FIG. 31 shows the effect of the combination therapy on median tumor
volume (TV) in a xenograft mouse model. The result show that in the
model used, VELCADE treatment alone had no effect on the tumor
volume. The combination with BT062 provided synergistic effects.
Notably the synergism resulted in a dose of 100 .mu.g/kg of the
immunoconjugate, when combined with a dose of 100 mg/kg VELCADE.
For synergy ratios, please refer to the table above.
EXAMPLE 3
BT062/Melphalan
RPMI cells have been implanted subcutaneously into nude mice. Mice
were randomized when tumor reached a total volume of approx 100
mm.sup.3. BT062 was injected intravenously at 2 different
concentrations: 400 .mu.g/kg and 100 .mu.g/kg; each based on the
molecular weight of the linked DM4. PBS served as negative control.
Per group, 8 mice with one tumor each (unilateral implantation)
were used. BT062 was dosed weekly followed by melphalan once weekly
(3 mg/kg) one day after BT062 injection intraperitoneally (results
not shown).
EXAMPLE 4
In Vivo Drug Combination Studies
BT062/Lenalidomide/Dexamethasone
While in vitro different cell lines showed a concentration
dependent CD138 decrease after 24 h lenalidomide incubation (FIG.
32(A) to (D)), in vivo drug combination studies showed that a
combination of 4 mg/kg, 20 mg/kg lenalidomide and 1.25 mg/kg
dexamethasone was highly effective in a L363 MM xenograft
model.
In this model, a highly aggressive CD138 expressing plasma cell
myeloma cell line L363 was subcutaneously implanted into NOD/SCID
mice. Treatment started when tumors reached a size of approx. 100
mm.sup.3. BT062 was injected intravenously once weekly on days 1,
8, 15, 22, 29 at concentrations of 2 mg/kg or 4 mg/kg either alone
or in combination with lenalidomide, which was given orally on days
0-4, 7-11, 14-18, 21-25 and 28-32 and Dexamethasone, which was
given intraperitoneally on days 0, 7, 14, 21 and 28. Tumor size was
measured once weekly. 4 mg/kg BT062 alone was active in reducing
the tumor growth. Combination of 4 mg/kg BT062 with Len/Dex showed
higher activity with regard to tumor growth inhibition leading than
the single agents (Len/Dex alone; BT062 alone) (FIG. 33).
Once given the above disclosure, many other features,
modifications, and improvements will become apparent to the skilled
artisan. Such other features, modifications, and improvements are
therefore considered to be part of this invention, the scope of
which is to be determined by summary of the invention and the
following claims.
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SEQUENCE LISTINGS
1
131448PRTArtificial SequenceAmino Acid sequence (predicted) of
heavy chain of chimeric human/mouse
antibodyCDR1(31)..(35)CDR2(51)..(68)CDR3(99)..(111) 1Gln Val Gln
Leu Gln Gln Ser Gly Ser Glu Leu Met Met Pro Gly Ala 1 5 10 15 Ser
Val Lys Ile Ser Cys Lys Ala Thr Gly Tyr Thr Phe Ser Asn Tyr 20 25
30 Trp Ile Glu Trp Val Lys Gln Arg Pro Gly His Gly Leu Glu Trp Ile
35 40 45 Gly Glu Ile Leu Pro Gly Thr Gly Arg Thr Ile Tyr Asn Glu
Lys Phe 50 55 60 Lys Gly Lys Ala Thr Phe Thr Ala Asp Ile Ser Ser
Asn Thr Val Gln 65 70 75 80 Met Gln Leu Ser Ser Leu Thr Ser Glu Asp
Ser Ala Val Tyr Tyr Cys 85 90 95 Ala Arg Arg Asp Tyr Tyr Gly Asn
Phe Tyr Tyr Ala Met Asp Tyr Trp 100 105 110 Gly Gln Gly Thr Ser Val
Thr Val Ser Ser Ala Ser Thr Lys Gly Pro 115 120 125 Ser Val Phe Pro
Leu Ala Pro Cys Ser Arg Ser Thr Ser Glu Ser Thr 130 135 140 Ala Ala
Leu Gly Cys Leu Val Lys Asp Tyr Phe Pro Glu Pro Val Thr 145 150 155
160 Val Ser Trp Asn Ser Gly Ala Leu Thr Ser Gly Val His Thr Phe Pro
165 170 175 Ala Val Leu Gln Ser Ser Gly Leu Tyr Ser Leu Ser Ser Val
Val Thr 180 185 190 Val Pro Ser Ser Ser Leu Gly Thr Lys Thr Tyr Thr
Cys Asn Val Asp 195 200 205 His Lys Pro Ser Asn Thr Lys Val Asp Lys
Arg Val Glu Ser Lys Tyr 210 215 220 Gly Pro Pro Cys Pro Ser Cys Pro
Ala Pro Glu Phe Leu Gly Gly Pro 225 230 235 240 Ser Val Phe Leu Phe
Pro Pro Lys Pro Lys Asp Thr Leu Met Ile Ser 245 250 255 Arg Thr Pro
Glu Val Thr Cys Val Val Val Asp Val Ser Gln Glu Asp 260 265 270 Pro
Glu Val Gln Phe Asn Trp Tyr Val Asp Gly Val Glu Val His Asn 275 280
285 Ala Lys Thr Lys Pro Arg Glu Glu Gln Phe Asn Ser Thr Tyr Arg Val
290 295 300 Val Ser Val Leu Thr Val Leu His Gln Asp Trp Leu Asn Gly
Lys Glu 305 310 315 320 Tyr Lys Cys Lys Val Ser Asn Lys Gly Leu Pro
Ser Ser Ile Glu Lys 325 330 335 Thr Ile Ser Lys Ala Lys Gly Gln Pro
Arg Glu Pro Gln Val Tyr Thr 340 345 350 Leu Pro Pro Ser Gln Glu Glu
Met Thr Lys Asn Gln Val Ser Leu Thr 355 360 365 Cys Leu Val Lys Gly
Phe Tyr Pro Ser Asp Ile Ala Val Glu Trp Glu 370 375 380 Ser Asn Gly
Gln Pro Glu Asn Asn Tyr Lys Thr Thr Pro Pro Val Leu 385 390 395 400
Asp Ser Asp Gly Ser Phe Phe Leu Tyr Ser Arg Leu Thr Val Asp Lys 405
410 415 Ser Arg Trp Gln Glu Gly Asn Val Phe Ser Cys Ser Val Met His
Glu 420 425 430 Ala Leu His Asn His Tyr Thr Gln Lys Ser Leu Ser Leu
Ser Leu Gly 435 440 445 2214PRTArtificial SequenceAmino Acid
sequence (predicted) of light chain of chimeric human/mouse
antibodyCDR1(24)..(34)CDR2(50)..(56)CDR3(89)..(97) 2Asp Ile Gln Met
Thr Gln Ser Thr Ser Ser Leu Ser Ala Ser Leu Gly 1 5 10 15 Asp Arg
Val Thr Ile Ser Cys Ser Ala Ser Gln Gly Ile Asn Asn Tyr 20 25 30
Leu Asn Trp Tyr Gln Gln Lys Pro Asp Gly Thr Val Glu Leu Leu Ile 35
40 45 Tyr Tyr Thr Ser Thr Leu Gln Ser Gly Val Pro Ser Arg Phe Ser
Gly 50 55 60 Ser Gly Ser Gly Thr Asp Tyr Ser Leu Thr Ile Ser Asn
Leu Glu Pro 65 70 75 80 Glu Asp Ile Gly Thr Tyr Tyr Cys Gln Gln Tyr
Ser Lys Leu Pro Arg 85 90 95 Thr Phe Gly Gly Gly Thr Lys Leu Glu
Ile Lys Arg Thr Val Ala Ala 100 105 110 Pro Ser Val Phe Ile Phe Pro
Pro Ser Asp Glu Gln Leu Lys Ser Gly 115 120 125 Thr Ala Ser Val Val
Cys Leu Leu Asn Asn Phe Tyr Pro Arg Glu Ala 130 135 140 Lys Val Gln
Trp Lys Val Asp Asn Ala Leu Gln Ser Gly Asn Ser Gln 145 150 155 160
Glu Ser Val Thr Glu Gln Asp Ser Lys Asp Ser Thr Tyr Ser Leu Ser 165
170 175 Ser Thr Leu Thr Leu Ser Lys Ala Asp Tyr Glu Lys His Lys Val
Tyr 180 185 190 Ala Cys Glu Val Thr His Gln Gly Leu Ser Ser Pro Val
Thr Lys Ser 195 200 205 Phe Asn Arg Gly Glu Cys 210
331DNAArtificial SequenceIgH primer MHV7 3atgggcatca agatggagtc
acagacccag g 31421DNAArtificial SequenceIgG1 constant region primer
MHCG1 4cagtggatag acagatgggg g 21530DNAArtificial SequenceIg kappa
primer MKV2 5atggagacag acacactcct gctatgggtg 30633DNAArtificial
SequenceIg kappa primer MKV4 6atgagggccc ctgctcagtt ttttggcttc ttg
33725DNAArtificial SequenceIg kappa primer MKV9 7atggtatcca
cacctcagtt ccttg 25820DNAArtificial Sequenceprimer MKC 8actggatggt
gggaagatgg 20950DNAArtificial Sequenceforward (For) primer
9agagaagctt gccgccacca tgattgcctc tgctcagttc cttggtctcc
501035DNAArtificial Sequenceoligonucleotide primer BT03
10caacagtata gtaagctccc tcggacgttc ggtgg 351135DNAArtificial
Sequenceoligonucleotide primer BT04 11ccaccgaacg tccgagggag
cttactatac tgttg 351241DNAArtificial Sequenceprimer g2258
12cgcgggatcc actcacgttt gatttccagc ttggtgcctc c 411345DNAArtificial
SequencePrimer g22949 13cgatgggccc ttggtggagg ctgaggagac ggtgactgag
gttcc 45
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References